LIMA, Peru -- U.S. Secretary of State Hillary Rodham Clinton repeated on Tuesday her statement taking sole responsibility for security at all of America's diplomatic missions, an attempt to clear a political obstacle for her boss, President Barack Obama, ahead of his second debate with Republican Mitt Romney.

"I take responsibility," Clinton said in a written statement. "I'm in charge of the State Department's 60,000-plus people all over the world (at) 275 posts."

With only weeks before the presidential election, outrage has crystallized around Vice President Joe Biden's claim in last week's debate with Republican vice presidential nominee Paul Ryan that "we weren't told" about requests for extra security at the consulate where assailants killed U.S. Ambassador Chris Stevens and three other Americans.

Congressional hearings revealed that the State Department was aware of, and rejected, several requests for increased security in Benghazi. Spokesmen for the State Department and the White House took pains Friday to make clear that Biden's "we" referred to the White House, where such requests would not go.

Clinton backed up Biden's assertion. "The president and the vice president certainly wouldn't be knowledgeable about specific decisions that are made by security professionals," she said Monday.

Three separate investigations into the attack are being conducted: an FBI probe into the deaths of the four Americans, an independent inquiry by a panel appointed by Clinton and the congressional hearings.

Initial reports attributed the cause of the violent attack as one of a number of spontaneous demonstrations in several Muslim countries over a film produced in the U.S. that had denigrated the Prophet Muhammad.

U.S. ambassador to the United Nations Susan Rice insisted on talk shows in the days after the event that the investigation up to that point showed no indication of a planned attack.

Within days, the White House reversed its position, saying new findings indicated the attack was intentional and coordinated.

"Everyone who spoke tried to give the information they had," Clinton's statement said. "As time has gone on, the information has changed, we've gotten more detail, but that's not surprising. That always happens."

She added, "What I want to avoid is some kind of political gotcha or blame game."