(CNN) -- President Obama said Friday that he was "surprised and deeply humbled" by the decision of the Norwegian Nobel Committee to award him the 2009 Nobel Peace Prize.
President Obama, speaking Friday, said the award was "an affirmation of American leadership."
The committee said it honored Obama for his "extraordinary efforts to strengthen international diplomacy and cooperation between peoples."
Obama said he viewed the decision less as a recognition of his own accomplishments and more as "a call to action."
The decision appeared to catch most observers by surprise. Nominations for the prize had to be postmarked by February 1, only 12 days after Obama took office. The committee sent out its solicitation for nominations last September, two months before Obama was elected president.
Obama had not been mentioned as among front-runners for the prize, and the roomful of reporters gasped when Thorbjorn Jagland, chairman of the Nobel committee, announced that the president was the winner.
The Nobel committee recognized Obama's efforts at dialogue to solve complex global problems, including working toward a world free of nuclear weapons. Watch CNN's Christiane Amanpour's analysis »
"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," the committee said.
Jagland said the decision was "unanimous" and came with ease. Watch the 2009 Nobel Peace Prize announcement »
He rejected the notion that Obama had been recognized prematurely for his efforts and said the committee wanted to promote the president just it had Mikhail Gorbachev in 1990 for his efforts to open up the Soviet Union. Ed Rollins: Obama now must earn it
"His diplomacy is founded in the concept that those who are to lead the world must do so on the basis of values and attitudes that are shared by the majority of the world's population," the committee said of Obama. Listen to Jagland explain why Obama was this year's choice »
Choosing a winner
Obama said he did not feel he deserved "to be in the company" of past Peace Prize winners, but would accept the prize while pushing for a broad range of international objectives, including nuclear nonproliferation, a reversal of the global economic downturn and a resolution of the Arab-Israeli conflict.
He also acknowledged the ongoing U.S. conflicts in Iraq and Afghanistan, noting that he is the "commander in chief of a country that is responsible for ending a war and working in another theater to confront a ruthless adversary that directly threatens the American people" and U.S. allies.
"This award is not simply about my administration," he said. It "must be shared" with everyone who strives for "justice and dignity." Watch Obama react to receiving the prize »
It was just before 6 a.m. that the president learned he had won the award, said Robert Gibbs, the White House press secretary. The announcement by the committee caught the White House off guard. One senior administration official said that "we were quite surprised."
Some analysts have speculated that the prize could give Obama additional clout as he forms a new strategy for the war in Afghanistan and attempts to engage Iran and North Korea. Another senior administration official told CNN he hopes the White House can "use it for the positive."
The domestic political consequences are unclear. Obama's supporters hope the prestige associated with the prize will strengthen the president's hand in the health care reform debate. A top Republican from George W. Bush's administration, however, argued that "this will backfire on them for a while" and asserted it was "a gift to the right." Zakaria: Nobel honors Obama's 'bold gambit'
Obama, the first African-American to win the White House, is the fourth U.S. president to win the prestigious prize and the third sitting president to do so.
Former Finnish President Martti Ahtisaari, last year's laureate, said it was clear the Nobel committee wanted to encourage Obama on the issues he has been discussing on the world stage.
"I see this as an important encouragement," Ahtisaari said.
The committee wanted to be "far more daring" than in recent times and make an impact on global politics, said Kristian Berg Harpviken, director of the International Peace Research Institute. Praise, skepticism greet Nobel announcement