"I am fully confident that I could serve our country ably and effectively in that role," Rice wrote in a letter to President Obama today. "However, if nominated, I am now convinced that the confirmation process would be lengthy, disruptive and costly – to you and to our most pressing national and international priorities."
"That trade-off is simply not worth it to our country," she added.
Rice has been criticized by Republicans for her response to questions about the terrorist attack on the U.S. consulate in Benghazi.
"The position of Secretary of State should never be politicized," Rice wrote. "As someone who grew up in an era of comparative bipartisanship and as a sitting U.S. national security official who has served in two U.S. Administration, I am saddened that we have reached this point, even before you have decided whom to nominate. We cannot afford such an irresponsible distraction from the most pressing issues facing the American people."
President Obama has accepted Rice's decision to remove her name from the running.
"While I deeply regret the unfair and misleading attacks on Susan Rice in recent weeks, her decision demonstrates the strength of her character, and an admirable commitment to rise above the politics of the moment to put our national interests first," Obama said in a written statement. "The American people can be proud to have a public servant of her caliber and character representing our country."