Obama's win was a surprise, as his presidency began only two weeks before the nomination deadline and many of his proposed initiatives have yet to bear fruit. The Norwegian Nobel Committee, however, commended the president's calls for peace and cooperation and the impact they have made on the global mood.
"Only 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," said committee chairman Thorbjoern Jagland. "We are not awarding the prize for what may happen in the future but for what he has done in the previous year. We would hope this will enhance what he is trying to do."
In his nearly 10 months in office, Obama has called for reductions in nuclear arms and is seeking to restart peace talks between Israelis and Palestinians. He has taken on challenges in Iraq, Afghanistan and Iran, which is feared to be exploring the building of a nuclear weapon.
Former Peace Prize winner Mohamed ElBaradei said Obama has already provided outstanding leadership in preventing nuclear proliferation. "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," ElBaradei said. "He has shown an unshakeable commitment to diplomacy, mutual respect and dialogue as the best means of resolving conflicts."
Obama is the third sitting U.S. president to win the award, following Theodore Roosevelt in 1906 and Woodrow Wilson in 1919.
The White House has not yet released an statement, but said the president is humbled by the honor.