The US President told a television audience from the White House that he would accept the award as a “call to action for nations to confront the challenges of the 21st century”, adding that it had to be “shared by

everyone who strives for justice and dignity”.

The Norwegian Nobel Committee hailed his “extra-ordinary efforts to strengthen international diplomacy and co-operation between peoples” and said he had restored multilateral diplomacy to the centre of the world stage. The prestigious award also carries a £900,000 payout.

While Mr Obama has boosted troop numbers in Afghanistan and his country’s relations with Iran remain tense over its nuclear programme, he has offered a message of peace to the Muslim world, sought to kick-start stalled negotiations in the Middle East, begun work with Dmitry Medvedev, his Russian counterpart, on reducing their countries’ nuclear arsenals and scrapped the missile shield planned for eastern Europe.

Nobel observers were shocked by the unexpected choice so early in the Obama presidency, which began just 12 days before the February nomination deadline. The feeling is that the President has received the award more as an incentive to continue his peacekeeping efforts than for his performance to date.

Mr Obama’s election and foreign policy appear to have caused a dramatic improvement in America’s image.

A recent 25-nation poll of 27,000 people found double-digit boosts to the percentage of people viewing the US favorably, after the indicator plunged during the presidency of George W Bush.

Former Norwegian prime minister Thorbjoern Jagland, the committee’s chairman, explained that the prize-

giving body had decided to delay informing the US leader of its decision. “Waking up a president in the middle of the night, this isn’t really something you do,” he said. Mr Obama woke up to the news a little before 6am.

Prime Minister Gordon Brown, who had spoken to the President via videophone on Thursday, sent him a private message of congratulations, Downing Street said.

However, the response around the world was mixed.

The Taliban swiftly condemned the award with its spokesman Zabihullah Mujahid saying: “He has done nothing for peace in Afghanistan.”

Mohamed ElBaradei, director-general of the UN International Atomic Energy Agency, who received the prize in 2005, said: “I cannot think of anyone today more deserving of this honour. In less than a year in office, he has transformed the way we look at ourselves and the world we live in and rekindled hope for a world at peace with itself.”

However, former Polish

president Lech Walesa, a Nobel Peace laureate in 1983, noted: “So soon? Too early. He has no contribution so far. He is still at an early stage. He is only beginning to act.”

Nicolas Sarkozy, the French premier, said the prize embodied the “return of America into the hearts of the people of the world”.

In the Middle East, Saeb Erekat, the main Palestinian peace negotiator, said the award could be a good omen for peace in the region.

However, Sami Abu Zuhr of the Islamist movement Hamas, which controls the Gaza Strip and opposes a peace treaty with Israel, said: “Obama has a long way to

go still and lots of work to do before he can deserve a reward.”

In Indonesia, Masdar Mas’udi, deputy head of the country’s largest Muslim organisation Nahdatul Ulama, said the award was a good thing, adding: “It’s appropriate because he is the only American president who has reached out to us in peace.”

However in Pakistan, Liaqat Baluch, a senior leader of the Jamaat-e-Islami, a

conservative religious party, said: “It’s a joke. How

embarrassing for those who awarded it to him because he’s done nothing for peace.”

Mr Obama becomes the third sitting US president to win the award: Theodore Roosevelt won it in 1906 and Woodrow Wilson in 1919.