The last-resort measure came after the Bank of Japan said business confidence had plummeted since the earthquake and tsunami hit on March 11, plunging the country into its worst crisis since World War II.

The UN atomic watchdog chief Yukiya Amano, meanwhile, said that the three-week-old Fukushima emergency, which Japan has predicted may last for months, meant an end to a “business as usual” approach to nuclear power.

His comments appeared borne out when Japan signalled it may weaken its ambitious greenhouse gas cut targets, which are based on a continued heavy reliance on low-carbon atomic power, in light of the disaster.

Japan has battled to prevent full reactor meltdowns at the tsunami-hit plant and poured thousands of tons of water onto overheating fuel rods, a stop-gap measure that has created highly radioactive run-off.

To free up storage space for that run-off – which has hampered crucial repair work and leaked into the Pacific – operator the Tokyo Electric Power Company (TEPCO) said it would have to get rid of less toxic water.

It insisted the release of the water – the equivalent of more than four Olympic sized swimming pools – would not harm marine life or seafood safety.

But a TEPCO official fought back tears when he announced the step, saying: “We have already caused such pain and nuisance to local residents. We cannot express how sorry we are to have to impose another burden.”

Prime Minister Naoto Kan’s top spokesman, Yukio Edano, said in a televised press conference: “We have no choice but to release water tainted with radioactive materials into the ocean as a safety measure.”

As a result of the massive water dumping operations, “highly radioactive waste water has accumulated at turbine buildings at Fukushima Daiichi, especially at the reactor unit two,” said another TEPCO official.

“There is a need to release already stored water in order to accept the additional waste water” totalling 10,000 tons, as well as 1,500 tons of water from pits under reactor units five and six, he said.

Contamination from the plant has been found in the air, ground, seawater and, at lower concentrations, in regional produce including vegetables, dairy products, beef and, most recently, shiitake mushrooms.

The nuclear emergency – which has in many ways overshadowed the quake and tsunami that killed 12,020 people and left 15,512 missing – has also hit the economy hard, sending stocks reeling and hitting manufacturing output.

An updated version of the central bank’s quarterly Tankan survey – a key influence on monetary policy – showed business confidence in the outlook for the next three months had plunged since the disaster.

The government is considering asking manufacturers to start work an hour earlier than usual to ease electricity demand during the summer, when air conditioner use peaks, Kyodo news agency reported.

Japan withdrew from the Copa America football tournament to be held in Argentina in July, saying it will need the period to catch up on domestic matches currently being postponed to avoid night-time electricity use.

In Vienna, UN International Atomic Energy Agency chief Amano said the disaster “has enormous implications for nuclear power and confronts all of us with a major challenge.”

“The worries of millions of people throughout the world about whether nuclear energy is safe must be taken seriously,” Amano said in an opening address to a special conference on nuclear safety.

But Amano insisted that the basic drivers behind interest in nuclear power – global energy demand, concerns about climate change, volatile fossil fuel prices and energy security – “have not changed as a result of Fukushima.”

Japan’s Edano earlier said that Tokyo’s climate goal – to cut emissions by 25 percent by 2020 from 1990 levels, if other big polluters do the same – was now open to review along with many other policies.

“Not only the 25 percent reduction target but also many other challenges that Japan is facing now should be examined at one point because many areas have been impacted by the quake disaster,” Edano said.

The Yomiuri Shimbun daily reported that the environment ministry’s top bureaucrat Hideki Minamikawa had told reporters at UN climate talks in Bangkok that “the reduction goal will be affected a great deal”.

Resource-poor Japan meets about one third of its energy demand from nuclear energy and relies heavily on Middle Eastern oil, while its companies are leaders in energy efficiency and green technologies.

Obama warned on Tuesday he had not dominated out supplying arms to rebels seeking to oust him, and said the “noose is tightening” round the Libyan strongman.

He additionally noted, however, that it didn’t seem nonetheless that Gaddafi was seeking to barter an exit from Libya, despite a fierce bombardment of his forces by a world coalition.

The Quinnipiac University survey found most voters were assured the US mission to defend civilians from Gaddafi might succeed, though there was an undercurrent of concern a few long engagement, with forty seven to forty one per cent hostile US involvement in Libya.

The president gave interviews to a few network tv news shows as a part of a firm defense of his Libya strategy, including an address to Americans and returning appearances by his national security team in Congress.

Obama’s comments mirrored a lucid try by US and allied forces to boost intolerable pressure on Gaddafi and his forces to drive him from power.

“Our expectation is that as we tend to still apply steady pressure, not solely militarily however additionally through these different means that, that Gaddafi can ultimately step down,” Obama said in his interview with NBC.

Obama cautioned during a speech to Americans on Monday, however, that though he would use force to shield civilians, an attempt to oust Gaddafi by force would replicate the carnage and monetary value of the Iraq war.

His comments on Tuesday followed a significant international conference on next steps in Libya in London where Italian Foreign Minister Franco Frattini told AFP that participants had “unanimously” agreed Gaddafi ought to leave Libya.

But Frattini said, as yet, no nation had created a proper proposal to supply Gaddafi exile.

Obama told ABC News that those around Gaddafi were being given cause to rethink their positions as his regime came beneath intense outside pressure.

“I assume what we’re seeing is that the circle around Gaddafi understands that the noose is tightening, that their days are most likely numbered, and that they are aiming to ought to assume through what their next steps are,” Obama said.

Obama additionally confided that he was thinking through the thought of arming opposition rebels in Libya, though had nonetheless to form a final call.

“We’re viewing all our choices at this time,” he said. “We are examining all choices to support the opposition,” he told ABC.

“I’m not ruling it out. however i am additionally not ruling it in,” he added on NBC, however cautioned that though Washington’s data of the identity, goals and make-up of the rebels was improving, it had been not nonetheless comprehensive.

Those members of the Libyan opposition who had met high US officers, together with Secretary of State Hillary Clinton, had been absolutely “vetted,” he said.

But some opposition people could also be unfriendly to the us, he added.

“That’s why i feel it is important for us to not jump in with each feet. however to fastidiously contemplate what are the goals of the opposition,” Obama told CBS.

Earlier in the week, the US military announced a shift from long-range guided missile attacks that have targeted command centres and anti-aircraft defences, to low-flying combat aircraft designed for close-range assaults against ground troops, nonetheless still insisted denied it had been directly supporting the rebels.

The aircraft are the A-10, designed for shut air support, particularly against tanks and armoured vehicles, and also the AC-130, a transport aircraft changed for shut combat.

Experts and former US military officers say bombing raids nearly always need clandestine “eyes on the bottom,” with forward air controllers from special forces or intelligence agencies citing targets for warplanes.

This was the case in Afghanistan, Iraq, Kosovo, Bosnia and different conflicts, consultants said.

Any call to arm Libyan rebels would cause intense international discussion over whether or not a world arms embargo on Libya would preclude such action.

Britain’s Prime Minister David Cameron has said the language of the embargo wouldn’t permit the provision of weapons. The White House has said, however, it believes the text will provide latitude to send arms to rebels.

Earlier, France’s Foreign Minister Alain Juppe said his country was ready to carry discussions with its allies over the likelihood of supplying military aid to the opposition movement.

And rebel forces said late Tuesday that French and US diplomatic envoys were headed to Benghazi, and said they were attempting to obtain arms from “friendly nations.”

Speaking at an international conference on Libya in London, the chief US diplomat also called for a “united front of diplomatic and political pressure” to force Gaddafi to step down after more than 40 years of power.

Military action will continue “until Gaddafi fully complies with the terms of (UN Security Council resolution) 1973, ceases his attacks on civilians, pulls his troops back from places they have forcibly entered, and allows key services and humanitarian assistance to reach all Libyans,” Clinton said.

The establishment of an immediate ceasefire was one of the top demands of the resolution authorizing “all necessary measures” to protect Libyan civilians, including air strikes on Gaddafi’s ground forces and a no-fly zone.

The resolution also demanded that the authorities in Tripoli “comply with their obligations under international law, including international humanitarian law, human rights and refugee law and take all measures to protect civilians and meet their basic needs, and to ensure the rapid and unimpeded passage of humanitarian assistance.”

However, Clinton said the international community had to go beyond military pressure to “deepen the isolation of the Gaddafi regime.

“This includes a united front of political and diplomatic pressure that makes clear to Gaddafi that he must go, that sends a strong message of accountability and that sharpens the choice for those around him,” she said.

“It includes financial pressure, through the vigorous enforcement of sanctions, authorised under UN Security Councils 1970 and 1973,” she said.

Resolution 1970 imposed bans on assets and travel on members of the regime as well as an arms embargo.

Clinton said the international community should not attempt to impose its will on the Libyan people but should “stand with them as they determine their own destiny.”

She added: “We believe that Libya’s transition should come through a broadly inclusive process that reflects the will and protects the rights of the Libyan people.”

Clinton, who earlier met Mahmud Jibril of the opposition Transitional National Council (TNC), said the TNC and a broad cross-section of Libyan civil society and “other stakeholders have a critical contribution to make.”

The United States has stopped short of recognising the TNC after US officials said they were trying to obtain a “clearer picture” about their aims.

She said the United Nations, African Union, the Arab League, the Organization of the Islamic Conference and the European Union “all have important roles to play” in supporting the transition.

Yang will meet his counterpart Kim Sung-Hwan and President Lee Myung-Bak during a two-day visit. A foreign ministry official told AFP the uranium programme was likely to be discussed.

The nuclear-armed North last November disclosed an apparently operational uranium enrichment plant to visiting US experts, giving it a potential second way of making atomic bombs.

Pyongyang claims the programme is for peaceful energy development but experts say it could easily be converted to produce weapons-grade uranium.

Japan and South Korea have urged the United Nations Security Council to take up the issue with a view to possible punishment.

China, the isolated North’s sole major ally, opposes taking the issue to the world body even though President Hu Jintao has expressed concern at reports on the programme.

China has warned its Security Council partners that it intends to block publication of a report on the subject, a diplomat at the United Nations told AFP last week.

The report says the North almost certainly has at least one other undisclosed enrichment-related facility and describes the uranium programme as a serious violation of UN sanctions.

Beijing insists that the issue be discussed when stalled six-party nuclear disarmament talks are revived. Yang was expected to brief Seoul officials on this week’s visit to Pyongyang by China’s vice foreign minister Zhang Zhijun.

Yang’s visit was originally scheduled for last November but postponed after the North’s deadly shelling of a South Korean border island. China’s failure publicly to condemn the North for that attack sparked irritation in Seoul.

The six-storey building collapsed after the 6.3 magnitude earthquake struck Christchurch on Tuesday.

“This particular site, CTV site, had a number of overseas students in it and my heart goes out to those families that are away knowing that some of their children, family have probably been killed in this incident,” said police operations commander Dave Lawry, referring to the Canterbury TV building.

“The situation is that we don’t believe this site is now survivable,” he added.

Lawry said the building, which housed the King’s Education College English language school on its third floor, was deteriorating and there were fears it could collapse further, endangering rescuers.

“At a certain point, I am not going to risk my staff for people who I believe there is no chance of survivability,” he told reporters.

He said it was a “sad fact” that emergency personnel were now moving resources from the building and would be redirecting them to other sites where there was a better chance of finding survivors.

Lawry said his heart went out to the family and friends of the presumed dead who had “come to our country and had bad luck”.

New Zealand media is reporting that 24 people have been pulled from the rubble of the CTV building, but that seven people had died inside and at least 22 others were listed as missing.

Lawry gave no details on the possible nationalities of those trapped inside the building but at least 23 Japanese are among the 300 missing after the 6.3-magnitude quake struck Christchurch at lunchtime on Tuesday.

Among them are 10 students from Toyama College of Foreign Languages who were in King’s Education College and are feared trapped.

Two South Korean students, a brother and a sister in their early 20s, are also missing and feared trapped in the same language school.

On its website King’s Education College said the largest number of its students came from the Philippines, Japan, South Korea, China and Thailand.

Earlier Wednesday, the head of New Zealand’s fire service said his officers had incorrectly reported 15 people were located and rescued from the Canterbury TV building.

“I have since been advised that it was a false report and that it is not true,” fire service national commander Mike Hall told TVNZ.

Hall said a briefing from fire service officials about a rescue at the Canterbury TV building, one of the worst-affected in the quake, was wrong.

The 27-year-old struck in the 48th and 50th minutes to add to German Thomas Hitzlsperger’s opener on his debut for the three-time FA Cup winners – Kiwi international defender Winston Reid added a fourth for his first goal for the club.

Burnley – who had beaten their opponents in their last meeting in the Premier League in February last year – reduced the deficit through Rodriguez but the four goal advantage was restored in time added on by Freddie Sears.

For 28-year-old Hitzlsperger – capped 52 times – it was the perfect start to his career with the club, which had been long delayed after suffering a serious injury following his transfer last June.

“It went so well tonight,” said Hitzlsperger, who is in his second spell in England having earlier in his career played for Aston Villa.

“I didn’t know what to expect after being out for so long. The fans must have forgotten about me.

“It’s been a tough time, so this is a special night for me.”

West Ham manager Avram Grant said that the decision at half-time to expose their opponents high defensive line had worked a treat – however he added he hoped his season ended differently to last year when as manager of Portsmouth they reached the FA Cup final and were relegated.

“Stay up and win the FA Cup final? I’d buy that right now,” said Grant, before adding that the return to fitness of Hitzlsperger had been crucial to confidence off and on the pitch.

Victory sees the Hammers earn an away trip to Premier League rivals Stoke.

The earthquake caused widespread damage in a city already recovering from a major quake in September last year.

“Multiple fatalities have been reported at several locations in the central city, including two buses crushed by falling buildings. A doctor and emergency services are attending,” police said in a statement.

“Other reports include multiple building collapses, fires in buildings in the central (city) and persons reported trapped in buildings.”

Television footage showed panicked workers fleeing from offices after the quake, which the US Geological Survey said hit at 12:51pm (2351 GMT Monday) five kilometres from the city at a depth of just four kilometres.

Christchurch airport was closed and police said they were evacuating the city centre.

Building frontages, already weakened by a 7.0 magnitude quake on September 4 collapsed onto the street, with witnesses saying there were people trapped inside.

Cars were buried under rubble and roads buckled as the tremor opened ruptures in the ground.

There were unconfirmed reports of injuries and that the local hospital had been evacuated.

“It was just unbelievable, it was so strong, nothing like I’ve ever experienced before, just horrible,” local shopkeeper Julian Hogday told TV3.

Negotiators were set to work through the night so the finance ministers and central bankers from the 20 top developed and developing economies could finalise a deal at a morning meeting.

In welcoming remarks on Friday, French President Nicolas Sarkozy warned the ministers that failure to put aside national interests and reach a deal would kill off the G20.

“The temptation to give priority to national interests is great. But let me tell you clearly — that would be the death of the G20,” said Sarkozy.

After the 2008 global economic crisis, world leaders decided to make the G20 the pre-eminent economic council instead of the G8.

Adopting indicators to make policy recommendations to avoid the emergence of new imbalances and a fresh crisis has been one of its major initiatives.

France wants an agreement as soon as possible so that in the second half of this year the International Monetary Fund can make economic policy recommendations to nations.

“We need a thermometer that works so we can examine the imbalances in all their aspects to make as useful a diagnosis as possible,” pleaded one negotiator.

But no consensus emerged about which indicators to use during a working dinner of the finance ministers and central bankers, a diplomatic source said.

China remained reluctant to agree to certain indicators under consideration, but there was no united front among emerging nations on the issue, said the source, who attended a working dinner.

“There is no consensus, but there is pressure from a majority for the adoption of a package of global indicators,” said the source.

“There are three options: either the whole package is adopted, nothing is adopted, or try to reach a compromise along the lines of main and secondary indicators, or even those which enter into force immediately and others later.”

A series of four indicators is under discussion.

Two measure imbalances within countries: the public deficit and debt, plus the level of private savings.

The other two measure external imbalances: the current account balance or trade balance, or foreign currency reserves or real exchange rates.

“China is reluctant, it prefers the trade balance to the current account balance,” which is favoured by other countries, said the source.

China is traditionally hostile to currency indicators as it has accumulated huge foreign currency reserves and the yuan is not freely convertible.

China last year resisted a US proposal to stabilise current account balances by setting a four-percent cap on countries’ deficits and surpluses.

The United States and other Western powers accuse China of holding down its currency to boost Chinese exports. China denies any such manipulation, blaming the imbalance on structural problems in its trade partners’ economies.

But Sarkozy said Friday that China had accepted to host a seminar on exchange rate policy in its southern city of Shenzen at the end of next month.

There was no “emerging nations front” on the indicators, however, said the source.

“India and Indonesia were supportive of the entire list,” as was Germany, which has also often been reluctant to support measures that would take aim at its huge trade surplus, said the source.

Speaking on behalf of the “BRICS” group of top emerging nations — Brazil, Russia, India, China and South Africa — Brazilian Finance Minister Guido Mantega said they prefer the trade balance to the current account balance as an indicator.

Sarkozy has vowed to reform the world monetary system and commodities markets during his year at the G20 helm, saying he aims to defend poor economies from currency and trade turbulence.

France and others have also talked of trying to curb the dollar’s supremacy as the world currency of reference. The US delegation says it wants to focus more on the effect of volatility in capital flows between countries.

The visit will be from June 30 to July 8, two months after their wedding in London’s Westminster Abbey on April 29.

“Prince William and Miss Catherine Middleton have accepted an invitation from the government of Canada to undertake a royal tour of Canada,” William’s office at St James’s Palace said in a statement.

The search and rescue pilot is directly in line to become Canada’s king after his father Prince Charles, the heir to the throne in the 16 Commonwealth realms, including Britain, Australia and New Zealand.

Canadian Prime Minister Stephen Harper said he was “delighted” by the visit, adding that it was a “testament to our country’s very close relationship with the royal family”.

The tour by William, 28, and Kate, 29, will include Alberta, the Northwest Territories, Prince Edward Island, Quebec and the capital Ottawa, said St James’s Palace.

A spokesman for the 16th-century London palace confirmed it would be the couple’s first official overseas visit following their marriage.

William, the son of Charles and the late Diana, princess of Wales, last visited Canada when he went to Vancouver aged 15 in 1998 with his father and brother Prince Harry. He was given a pop star’s welcome and was mobbed by teenage girls.

The brothers also toured Ontario province with their parents in 1991.

Diana died in a car crash in Paris in 1997, the year after she and Charles divorced.

The St James’s Palace spokesman added: “Prince William was keen to be able to visit Canada for himself as an adult, and to be able to show his wife a country that is close to his family’s heart.”

Canada is a Commonwealth realm, meaning that Queen Elizabeth II is its head of state and sovereign and William would not be visiting as a foreign royal but as a prince of Canada.

Queen Elizabeth and her husband Prince Philip went to Canada last July and in 2009 Charles and his second wife Camilla, Duchess of Cornwall also visited.

Harper said Canada “looks forward to welcoming the young couple”.

“Their decision to come to Canada first is a testament to our country’s very close relationship with the royal family — a bond of loyalty and affection illustrated by the crowds that turned out for Her Majesty Queen Elizabeth and His Royal Highness The Duke of Edinburgh last year,” he said.

“It is my sincere hope that their tour will be the start of a lasting relationship with Canada by the royal couple,” he added.

Canada is a common destination with the royals.

Queen Elizabeth has toured the realm over 20 times, more than any other country.

It will be seen by commentators as a safe option for a well-received overseas visit by the newlyweds, and a straightforward introduction to royal tours for Middleton.

She will have to get used to the long hours, relentless travelling and varied engagements that are part of the rigours of such trips.

The itinerary is likely to include the usual setpieces of official banquets, welcoming ceremonies involving guards of honour, and walkabouts.

It is thought the couple will take part in Canada Day celebrations in Ottawa on July 1.

News of the trip came a day after Diana’s brother Earl Charles Spencer announced that he was to tie the knot with Canadian charity boss Karen Gordon,his third marriage.

That wedding on June 18 will be at Althorp in Northamptonshire, central England, the Spencer family home where Diana is buried.

Peter Phillips, the queen’s eldest grandson and William’s cousin, married Canadian management consultant Autumn Kelly in 2008.

As excitement grew in Britain ahead of April 29, William on Monday said he had asked Harry to be his best man, while his fiancee had asked her sister Philippa to be maid of honour.

Schools and a major airport were closed as Tropical Cyclone Carlos formed off the far-flung northern city, which was hit by floods and downed power lines during a night of extreme weather.

Public broadcaster ABC said streets were flooded, while one house and an ambulance were crushed by falling trees. The weather bureau said some Darwin suburbs received up to 350 millimetres (14 inches) of rain in 24 hours.

Carlos was measured at category one on a scale of one to five. It was expected to peak at category two Thursday as it slowly circles away from Darwin and heads south-west, skimming the sparsely inhabited coastline.

Residents of Darwin, which has a population of about 120,000 and was largely rebuilt after being devastated by Cyclone Tracy in 1974, were warned to secure belongings and make plans to evacuate if their homes are not cyclone-proof.

The Bureau of Meteorology said winds were already gusting at up to 110 kilometres (68 miles) per hour and were expected to reach 130 kilometres, while Carlos would also bring abnormally high tides and some coastal flooding.

Relaying authorities’ advice, the bureau told residents that “now is the time to make final preparations to your home shelter or identify which public emergency shelter to use”.

Carlos comes soon after category-five Cyclone Yasi ploughed into northeastern Australia’s Great Barrier Reef coast, destroying small towns and wreaking Aus$1 billion in damage, but miraculously not causing any deaths.

Another tropical low off resource-rich Western Australia was expected to intensify to a category-three cyclone late Thursday but was tracking away from the coast, the bureau added.

Australia has been hit by four tropical cyclones since January 1 and suffered weeks of devastating flooding which killed 35 people, swamped tens of thousands of homes and brought Brisbane, its third-largest city, to a halt.

The wild weather has been linked to an especially strong La Nina weather pattern in the Pacific, which traditionally brings cyclones and floods to the vast country.