The withdrawal, which will be complete this month, fulfills a promise candidate Obama made in 2008 to pull out all troops from what he called a "dumb war."
Making his opposition to the war in Iraq a pivotal part of his campaign, candidate Obama promised to pull all U.S. combat troops out of the country by 2009.
"I opposed the war in Iraq before it began, and would end it as president," then-Sen. Obama wrote in a New York Times op-ed in 2008. "I believed it was a grave mistake to allow ourselves to be distracted from the fight against al Qaeda and the Taliban by invading a country that posed no imminent threat and had nothing to do with the 9/11 attacks."
Republicans have assailed Obama for pulling U.S. troops out of Iraq, with many saying it's too early.
"The meeting between President Obama and Prime Minister Maliki today cannot obscure the fact that both men have failed in their responsibilities with regard to our shared security interests," Sen. John McCain, R-Ariz., said in a statement. "All of the progress that both Iraqis and Americans have made, at such painful and substantial cost, has now been put at greater risk."
Virtually all 2012 candidates have criticized the president's decision. Former Massachusetts Gov. Mitt Romney called it a "failure to deliver."
Front-runner Newt Gingrich has blasted Obama for ushering in failure, even though he once said in a Newsweek interview that Americans can't win in Iraq.
Obama's supporters, however, charge that Republicans' criticism is bogus, especially because the Iraqi democratic government that the United States sought to create doesn't want troops to stay.
"They are on Mars," said Jon Stolz, founder of VoteVets who returned from duty in Iraq a week ago. "If the Republicans want to make it an issue they can, and they will lose on it. They are better off not talking about it."
ABC News' Luis Martinez contributed to this report.