US President Barack Obama won the 2009 Nobel Peace Prize on Friday for "his extraordinary efforts to strengthen international diplomacy and cooperation between peoples," the Norwegian Nobel Committee said, citing his outreach to the Muslim world and attempts to curb nuclear proliferation.

The stunning choice made Obama the third sitting US president to win the Nobel Peace Prize and shocked Nobel observers because Obama took office less than two weeks before the February 1 nomination deadline. Obama's name had been mentioned in speculation before the award but many Nobel watchers believed it was too early to award the president.

White House press secretary Robert Gibbs said Obama woke up to the news a little before 6 a.m. The White House had no immediate comment on the announcement, which took the administration by surprise.

The Norwegian Nobel Committee decided not to inform Obama before the announcement because it didn't want to wake him up, committee chairman Thorbjoern Jagland said. RELATEDOren: Obama approval in Israel must improvePeres, Barak congratulate Barack Obama

"Waking up a president in the middle of the night, this isn't really something you do," Jagland said.

The Nobel Committee lauded the change in global mood wrought by Obama's calls for peace and cooperation but recognized initiatives that have yet to bear fruit: reducing the world stock of nuclear arms, easing American conflicts with Muslim nations and strengthening the US role in combating climate change.

"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," Jagland said. "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 it attached special importance to Obama's vision of, and work for, a world without nuclear weapons.

Obama's election and foreign policy moves caused a dramatic improvement in the image of the US around the world. A 25-nation poll of 27,000 people released in July by the Pew Global Attitudes Project found double-digit boosts to the percentage of people viewing the US favorably in countries around the world. That indicator had plunged across the world under US president George W. Bush.

"Obama has as president created a new climate in international politics. Multilateral diplomacy has regained a central position, with emphasis on the role that the United Nations and other international institutions can play," the committee said.

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.

Archbishop Desmond Tutu of South Africa, who won the prize in 1984, said Obama's award shows great things are expected from him in coming years.

"It's an award coming near the beginning of the first term of office of a relatively young president that anticipates an even greater contribution towards making our world a safer place for all," Tutu said. "It is an award that speaks to the promise of President Obama's message of hope."