U.S. President Barack Obama comments on winning the 2009 Nobel Peace Prize while delivering a statement in the Rose Garden of the White House in Washington on Friday. (Jason Reed/Reuters)

U.S. President Barack Obama says he is deeply humbled by the Norwegian Nobel committee for selecting him as the winner of the 2009 Nobel Peace Prize and will accept it as a "call to action."

"I will accept this award as a call to action — a call for all nations to confront the challenges of the 21st century," Obama said in a press conference from the White House Rose Garden on Friday morning.

The Norwegian Nobel committee said the president was selected "for his extraordinary efforts to strengthen international diplomacy and co-operation between people."

The committee attached special importance to Obama's vision and work for a world without nuclear weapons in the prize citation, which was read in Oslo on Friday.

"The vision of a world free from nuclear arms has powerfully stimulated disarmament and arms control negotiations," the citation said.

Chair of the Norwegian Nobel committee, Thorbjorn Jagland, announces the 2009 Peace Prize in Oslo on Friday. (Torbjorn Gronning/Associated Press)

But the president said he isn't sure he "deserves to be in the company of so many transformative figures that have been honoured by this prize," Obama said, adding that previous Nobel laureates have been an inspiration to setting his own global goals.

Though Obama's name had been mentioned in speculation before the award, many Nobel watchers had believed it was too early to award it to the president and the selection is drawing mixed reaction from around the world. Obama would have been in the White House for less than two weeks before the Feb. 1 nomination deadline for this year's prize.

Gasps could be heard in the room where the award citation was read when Obama's name was announced.

The president said he does not "view [the award] as a recognition of my own accomplishment," but rather a recognition of goals he has set for the United States and the world. The award must be "shared by everyone who strives for justice and dignity," he said.

Norwegian Nobel committee chair Thorbjorn Jagland told CNN that the five-member committee had unanimously voted to select Obama as the Nobel laureate.

Jagland told CBC News the committee expected criticism about the selection. But the prize is meant to help "strengthen his role and his policy," he said.

Though Obama has been president for less than a year it has been "enough time to inspire the world," Jagland said.

The Nobel committee said Obama has created a new climate in international politics that has focused on multilateral diplomacy and an emphasis on the role of the United Nations and other international institutions.

"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 citation said.

'World's leading spokesman'

Obama is the third sitting U.S. president to win the Peace Prize. President Theodore Roosevelt won the award in 1906 and President Woodrow Wilson won in 1919.

Norwegian officials have confirmed the president will travel to Oslo on Dec. 10 to receive the award. Winners of the award receive an award of $1.5 million, a diploma and an invitation to the prize ceremonies in Stockholm on Dec. 10, the anniversary of Alfred Nobel's death in 1896.

"For 108 years, the Norwegian Nobel committee has sought to stimulate precisely that international policy and those attitudes for which Obama is now the world's leading spokesman," the citation said.

The committee endorsed Obama's statement that "now is the time for all of us to take our share of responsibility for a global response to global challenges."

Later on Friday, White House spokesman Robert Gibbs said Obama will donate the entire cash award to various charities, though the president has yet to decide which organizations will benefit.

'Long way to go'

While some Nobel laureates and former world leaders praised Obama's win, other groups called the award premature.

"Obama has a long way to go still and lots of work to do before he can deserve a reward," Hamas official Sami Abu Zuhri told Reuters. "Obama only made promises and did not contribute any substance to world peace."

A record 205 nominations were received for the prize this year.

Zimbabwe's Prime Minister Morgan Tsvangirai, Colombian Senator Piedad Cordoba, Chinese dissident Hu Jia, French-Colombian politician Ingrid Betancourt and Afghan women's rights activist Simi Samar were considered key contenders for the prize.

In his 1895 will, Alfred Nobel stipulated that the peace prize should go "to the person who shall have done the most or the best work for fraternity between the nations and the abolition or reduction of standing armies and the formation and spreading of peace congresses."

Grand gestures a Nobel tradition

Unlike the other Nobel Prizes, which are awarded by Swedish institutions, he said the peace prize should be given out by a five-member committee elected by the Norwegian parliament. Sweden and Norway were united under the same crown at the time of Nobel's death.

The committee has taken a wide interpretation of Nobel's guidelines, expanding the prize beyond peace mediation to include efforts to combat poverty, disease and climate change.

The committee is famous for making grand symbolic gestures aimed at influencing the world agenda, such as in 1989 when, in the wake of the Tiananmen massacre, the prize went to the Dalai Lama, the exiled Tibetan spiritual leader.

Former Finnish president Martti Ahtisaari received the award in 2008 for his decades of work trying to build lasting peace in various parts of the world.

The Nobel announcement is the fifth of six awards focusing on medicine, physics, chemistry, economics, literature and the peace prize, which will be announced through Oct. 12.

With files from The Associated Press