WASHINGTON -- United Nations Ambassador Susan Rice took herself out of the running Thursday to be the next secretary of state, bowing to a torrent of criticism by Republicans on Capitol Hill over remarks she made after a deadly attack on U.S. diplomatic facilities in Benghazi, Libya.

Rice wrote in a letter to President Barack Obama that she was confident she could serve in the nation’s highest diplomatic post but that she wanted to spare the nation what would have been a contentious confirmation process at the onset of Obama’s second term.

“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,” she wrote. “That trade-off is simply not worth it to our country.”

Obama had never said he would appoint Rice, but she had widely been considered one of the president’s top choices to replace Secretary of State Hillary Clinton, who plans to leave as soon as a successor is named. The most prominent name mentioned as a possible nominee now is Sen. John Kerry, D-Mass., the chairman of the Senate Foreign Relations Committee and his party’s 2004 presidential nominee. As a member of the Senate, he likely would win easy confirmation from his colleagues.

Rice will continue to serve as ambassador and in Obama’s Cabinet – she will meet with him at the White House on Friday.

Members of the Congressional Black Caucus expressed disappointment that an African-American woman they called qualified was denied a chance to serve in the high-profile position.

She would have been the third African-American in the spot after Republicans Colin Powell and Condoleezza Rice and the fourth woman after Madeleine Albright, Rice and Clinton.

The president repeatedly defended Rice from criticisms, led by Republican Sens. Lindsey Graham of South Carolina and John McCain of Arizona, that she misled Americans after the attack in Libya that killed four Americans. And he appeared to be ready to fight for her.

“If Senator McCain and Senator Graham want to go after somebody, they should go after me,” he said at a White House news conference the week after his re-election. “To besmirch her reputation is outrageous.”

In a statement Thursday, Obama called Rice an “extraordinarily capable, patriotic and passionate public servant,” and he credited her with helping secure international support for sanctions against Iran and North Korea, achieve an independent South Sudan and advocate for human rights.

“I have every confidence that Susan has limitless capability to serve our country now and in the years to come, and know that I will continue to rely on her as an adviser and friend,” Obama said. “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. The American people can be proud to have a public servant of her caliber and character representing our country.”

Late last month, Rice took the unusual step of meeting with Republican lawmakers who opposed her potential nomination. Normally, nominees make those visits to Capitol Hill after they’re nominated.