Oslo, Norway (CNN) -- President Obama accepted the Nobel Peace Prize in Norway on Thursday but acknowledged the questions surrounding the award.
Obama, along with first lady Michelle Obama, walked into Oslo City Hall at 1 p.m. to a trumpet fanfare and sustained applause.
"I receive this honor with deep gratitude and great humility," he said. "It is an award that speaks to our highest aspirations -- that for all the cruelty and hardship of our world, we are not mere prisoners of fate. Our actions matter, and can bend history in the direction of justice.
"And yet I would be remiss if I did not acknowledge the considerable controversy that your generous decision has generated. In part, this is because I am at the beginning, and not the end, of my labors on the world stage."
Obama said his accomplishments are "slight" in comparison to previous recipients of the prize, and that other nominees may be more deserving.
"But perhaps the most profound issue surrounding my receipt of this prize is the fact that I am the commander in chief of the military of a nation in the midst of two wars," he said.
His trip to Norway comes nine days after he announced plans to deploy additional U.S. troops to Afghanistan, one of two countries where the United States is fighting a war.
In his Nobel speech, Obama expounded on the concept of "just war" and the necessity of the use of force.
"I do not bring with me today a definitive solution to the problems of war," Obama said. "What I do know is that meeting these challenges will require the same vision, hard work, and persistence of those men and women who acted so boldly decades ago. And it will require us to think in new ways about the notions of just war and the imperatives of a just peace."
The troop surge decision by Obama, who has pledged to start withdrawing troops from Afghanistan after 18 months, comes amid rising U.S. casualties and a Taliban resurgence.
While pledging the additional troops in a speech December 1 at the U.S. Military Academy at West Point, New York, the president said: "Huge challenges remain. Afghanistan is not lost, but for several years it has moved backwards."
It is "our vital national interest to send an additional 30,000 U.S. troops" to the war-torn nation to help thwart the Taliban, Obama said.
The Nobel Prize win, announced in October, elicited swift reaction. Some hailed the choice, while others questioned what Obama had accomplished to deserve it. The February 1 nomination deadline came less than two weeks after his inauguration.
The Nobel decision was less a recognition of his accomplishments and more "a call to action," Obama said at the time.
After the ceremony, the Obamas will attend an evening award banquet. The prize includes a $1.4 million check, a gold medal and a diploma.