US President Barack Obama receives Nobel Peace Prize in Oslo

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.

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."

/CNN/