US President Barack Obama has won the Nobel Peace Prize for his calls to reduce the world's stockpile of nuclear weapons and working for world peace.
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Mr Obama was honoured 'for his extraordinary efforts to strengthen international diplomacy and cooperation between peoples', the head of the Norwegian Nobel Committee Thorbjørn Jagland said.
An administration official has said Mr Obama felt 'humbled' to win Nobel Peace Prize.
Taoiseach Brian Cowen has offered his congratulations to Mr Obama.
In a statement, Mr Cowen said: 'On behalf of the Irish people, I wish to warmly congratulate President Obama on this magnificent achievement. The Nobel Committee has rightly recognised the President's endeavours in diplomacy.
'Ireland has consistently supported the need for sustained diplomatic engagement on disarmament and I welcome the US President's efforts in this regard.'
The first African American to hold his country's highest office, Mr Obama has called for disarmament and worked to restart the stalled Middle East peace process since taking office in January.
The decision to award one of the world's top accolades to a president less than nine months into his first term, who has yet to score a major foreign policy success, comes as a major surprise.
The Norwegian Nobel Committee praised Mr Obama for 'his extraordinary efforts to strengthen international diplomacy and cooperation between peoples'.
‘Very rarely has a person to the same extent as Obama captured the world's attention and given its people hope for a better future,’ the committee said in a citation.
In a speech in Prague in April, Mr Obama declared: 'So today, I state clearly and with conviction America's commitment to seek the peace and security of a world without nuclear weapons.'
But he was not the first US president to set that goal, and acknowledged it might not be reached in his lifetime.
On other pressing issues, he is still searching for breakthroughs on Iran's disputed nuclear programme and on the stalled Middle East peace process.
Israel's foreign minister yesterday said that there was no chance of a peace deal for many years.
The chief Palestinian peace negotiator, Saeb Erekat, has welcomed the award to Mr Obama.
'We hope that he will be able to achieve peace in the Middle East and achieve Israeli withdrawal to 1967 borders and establish an independent Palestinian state on 1967 borders, with Jerusalem as its capital,' he told Reuters.
In Gaza, however, an Islamic Jihad leader, Khaled Al-Batsh, condemned the Nobel committee decision.
'Obama's winning the peace prize shows these prizes are political, not governed by the principles of credibility, values and morals,' he told Reuters.
'Why should Obama be given a peace prize while his country owns the largest nuclear arsenal on Earth and his soldiers continue to shed innocent blood in Iraq and Afghanistan?'
Iran said the award should prompt Mr Obama to start working towards ending injustice in the world.
An aide to Iranian President Mahmoud Ahmadinejad said: 'We hope that this gives him the incentive to walk in the path of bringing justice to the world order.'
'We are not upset and we hope that by receiving this prize he will start taking practical steps to remove injustice in the world.'
Last month Mr Obama chaired a historic meeting of the UN Security Council, which unanimously approved a US-drafted resolution calling on nuclear weapons states to scrap their arsenals.
Mr Obama is the third senior US Democrat to win the prize this decade after former Vice President Al Gore won in 2007 along with the UN climate panel and Jimmy Carter in 2002.
The prize worth 10 million Swedish crowns (almost €1m) will be handed over in Oslo on 10 December.
