Responses from three Americans -

Mike Huckabee and Tim Pawlenty — both potential 2012 presidential contenders — urged restraint.

"There will be an outcry from those on the right who will say that Obama's nomination, made two weeks into his Presidency, is impossible to justify, but I think such an outcry will sound like right-wing whining," Huckabee said in a statement. "The better response is simply to allow those on the left to explain what he did in his first two weeks as President that merited such recognition."

Pawlenty, speaking on NPR, said there "will be some people who are saying 'Was it based on good intentions and thoughts or is it going to be based on good results?'"

"But I think the appropriate response is when anybody wins a Nobel Prize, that is a very noteworthy development and designation and I think the appropriate response is to say 'Congratulations,'" said the Minnesota governor.


John McCain, on CNN: "I can't divine all their intentions, but I think part of their decision-making was expectations. And I'm sure the president understands that he now has even more to live up to. But as Americans, we're proud when our president receives an award of that prestigious category.