Most European leaders hailed the Nobel committee's choice of President Obama for the peace prize, with many saying the gesture should encourage people worldwide to work for nuclear disarmament and resolve regional disputes.
French President Nicolas Sarkozy said the Nobel honor is a tribute to Mr. Obama's commitment to "tolerance and dialogue between states, cultures and civilizations."
The French leader said the choice of Mr. Obama confirms the "return of America into the hearts of the people of the world."
German Chancellor Angela Merkel said the peace prize is "an incentive to the president and to us all" to do more for peace and, especially, to do more to remove the threat of nuclear weapons.
Last year's peace laureate, former Finnish President Martti Ahtisaari, said he believes the Nobel committee was trying to spur Mr. Obama to concentrate on settling the Israeli-Palestinian dispute, which he said is in the spirit of the will of the prize's founder, industrialist Alfred Nobel.
Others disagreed, however, saying the prize should reflect achievements and accomplishments.
Mairead Corrigan Maguire, the Northern Ireland peace activist who won the Nobel prize in 1976, told reporters in Britain the choice of Mr. Obama was "very sad." She said the U.S. president "has yet to prove that he will move seriously on the Middle East" or "that he will end the war in Afghanistan."