(CNN) -- President Barack Obama won the 2009 Nobel Peace Prize on Friday, a stunning decision that comes just eight months into his presidency.
The Norwegian Nobel Committee said it honored Obama for his "extraordinary efforts to strengthen international diplomacy and cooperation between peoples."
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, uttered the president's name.
The Nobel committee recognized Obama's efforts at dialogue to solve complex global problems including working toward a world free of nuclear weapons.
"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.
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 in his efforts to open up the Soviet Union.
"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.
Obama learned that he had won the award just before 6 a.m., said Robert Gibbs, the White House spokesman. The president was humbled to have won, Gibbs said.
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 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."
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.
Wangari Muta Maathai, the Kenyan environmentalist who won the 2004 Peace Prize, said the win for Obama, whose father was Kenyan, would help Africa move forward.
"I think it is extraordinary," she said. "It will be even greater inspiration for the world. He has shown how we can probably come together, work together in a cooperative way."
Mohamed ElBaradei, who won the 2005 Peace Prize for his efforts to prevent nuclear energy being used for military means, said Obama deserved to win for his efforts to bring Iran to the table for direct nuclear talks with the United States.
"I could not think of anybody who is more deserving," said ElBaradei, the chief of the International Atomic Energy Agency.
The award comes at a crucial time for Obama, who currently has multiple administration officials dispatched on global peace missions.
Obama's envoy to the Middle East, George Mitchell, has returned to the region to advocate for peace negotiations between Israelis and Palestinians. Mitchell met Thursday with Israeli President Shimon Peres. He plans to meet Friday with Prime Minister Benjamin Netanyahu before talking with Palestinian leaders in the West Bank.
Secretary of State Hillary Clinton starts a six-day trip to Europe and Russia on Friday. On the trip, the secretary will discuss the next steps on Iran and North Korea, and international efforts to have the two countries end their nuclear programs.
The centerpiece of the trip will be her visit to Moscow, where she will work toward an agreement to take the place of the Start II arms control pact, which expires December 5. She also will address the new bilateral presidential commission that is working on a broad range of issues, from arms control to health.
"This is an encouragement to this president to continue to follow through on those commitments when, inevitably, he hits the bump in the road," said CNN Chief National Correspondent John King.
"The committee is essentially saying 'Stay at it, Mr. President. You have our prestige behind you now.'"
King also noted that the Nobel Committee pushes "multilateralism around the world (and) very much disliked the prior U.S. president (George W. Bush). ... This is in part a reflection of that as well."
Bush was heavily criticized during his presidency for what some observers claimed was an excessive reliance on unilateral action and U.S. military power.
In a statement announcing its decision, the committee stated that multilateral diplomacy "has regained a central position, with emphasis on the role that the United Nations and other international institutions can play. Dialogue and negotiations are preferred as instruments for resolving even the most difficult international conflicts."
The decision of the international committee to award Obama the prize highlights the sharp contrast in views towards the president at home and abroad.
Obama remains extraordinarily popular overseas, particularly in Western Europe. A recent Pew Research Center survey found over three quarters of respondents in Britain, Germany, France, and Spain approve of Obama's foreign policy.
In the United States, however, Obama's overall approval ratings have declined. An October 1-5 Associated Press poll showed that 56 percent of Americans approve of Obama's job performance. A September 17-20 NBC/Wall Street Journal poll found that only half of all Americans back his handling of foreign policy.
The split perception was illustrated earlier this year by a U.S. university's decision to deny Obama an honorary degree when he delivered a commencement address at the school. While the Nobel Committee on Friday praised Obama for his "extraordinary effort," a spokesman for Arizona State University said last spring that Obama's "body of work is yet to come. That's why we're not recognizing him with a degree at the beginning of his presidency."
The last sitting U.S. president to win the peace prize was Woodrow Wilson in 1919. The other was Theodore Roosevelt in 1906. Jimmy Carter had been out of office for more than two decades when he won in 2002.
This year's Peace Prize nominees included 172 people -- among them three Chinese dissidents, an Afghan activist and a controversial Colombian lawmaker -- and 33 organizations, the highest number of nominations ever.
The Nobel recipient receives a prize of about $1.4 million.