US President Barack Obama has been awarded the 2009 Nobel Peace Prize.
The Nobel Committee said he won it for "his extraordinary efforts to strengthen international diplomacy and co-operation between peoples".
The committee highlighted Mr Obama's efforts to support international bodies and promote nuclear disarmament.
Mr Obama - woken up with the news early on Friday - said in an address at the White House that he was "surprised and deeply humbled" by the award.
He said he did not feel he deserved to be in the company of some of the "transformative figures" who had previously received the award.
Speaking outside the White House, he said he would accept the prize as a "call to action".
There were a record 205 nominations for this year's peace prize. Zimbabwean Prime Minister Morgan Tsvangirai and Chinese dissident Hu Jia had been among the favourites.
