Secretary of State Hillary Rodham Clinton speaks at the State Department in Washington Oct. 12, 2012, during her meeting with Italian Foreign Minister Giulio Terzi. / AP Photo
Updated at 2:38 p.m. ET
WASHINGTON As Republicans heap criticism on Vice President Joe Biden for claiming "we weren't told" about requests for extra security at the U.S. consulate in Benghazi, Secretary of State Hillary Rodham Clinton said Friday the precise details of the deadly Sept. 11 attack on the compound in Libya still remain unclear.
One month after the attack that killed the U.S. ambassador to Libya and three other Americans, Clinton said the administration is committed to uncovering the truth about what happened.
"There is much we still don't know and I am the first to say that," Clinton told reporters at the State Department after meeting with Italian Foreign Minister Giulio Terzi.
"But as someone who has been at the center of this tragedy from the beginning, I do know this: there is nobody in this administration motivated by anything other than trying to understand what happened," she said.
"We are doing all we can to prevent it from ever happening again anywhere and, of course, we are, as a government, doing what it takes to track down those who are responsible."
Clinton didn't answer questions from CBS News about what she was doing during the attack, CBS News correspondent Margaret Brennan reports. In a hearing earlier this week on Capitol Hill, Charlene R. Lamb, a deputy assistant secretary for diplomatic security, testified that Clinton was monitoring the attack electronically.
"I'm going to be, as I have been from the very beginning, cooperating fully with the investigations that are ongoing because nobody wants to know more about what happened and why than I do, and I think I'll leave it at that," Clinton said Friday.
Later, at her daily press briefing, State Department spokeswoman Victoria Nuland told reporters she thought that Clinton wanted the focus to be on the department's review of the assault and not her personal timeline.
"She's not that interested in focusing on herself, but -- but, you know, obviously she was here very late that night," said Nuland, adding that Clinton was receiving regular updates from officials. "She was making phone calls to senior people, and so she was obviously very much involved, but I think she was not interested in sort of giving a personal tick-tock. It's not the way she operates."
At a speech later to a Washington think tank, Clinton said the United States must continue sending diplomats and aid workers to the Arab world's emerging democracies, saying the U.S. cannot retreat from dangerous countries and that Americans remain leaders in "hard places where America's interests and values are at stake."
Republicans have seized on the incident as a sign of weakness in President Obama's foreign policy and criticized the administration for at first suggesting that the attack was motivated by anger at an anti-Islam film produced in the United States. That explanation has now been discarded as evidence mounts that it was a well-organized terrorist attack.
Republicans have also denounced the administration for denying several appeals for additional security at the consulate in the months before the attack. And they have seized on Biden's statement in Thursday's vice presidential debate that "we weren't told they wanted more security there."
On Wednesday, two former security officials testified before Congress that their requests for more manpower were either ignored or rejected. Lamb and senior State Department officials acknowledged that that was the case but insisted that there was no evidence that more security would have thwarted or otherwise mitigated the attack.
At the debate, Biden said, "We did not know they wanted more security again."
White House spokesman Jay Carney said Biden was referring specifically to the White House, which wouldn't receive such requests.
Following Wednesday's hearing, Undersecretary of State Patrick Kennedy told reporters at an impromptu press conference that the U.S. did what it was supposed to, and intends to keep working with the fragile Libyan government closely.
Amid persistent questioning about the alleged lack of sufficient security in Benghazi, State Department officials have been defensive about their procedures. Kennedy, at his press conference, echoed that defense, saying it is impossible for diplomatic missions to only operate where security is robust.
"The State Department goes into inherently dangerous places all the time. That's our mission. We have to operate forward. We're there when the military is not there. We're there when others are not there. If we were to end risk, we would close 275-odd missions and withdraw to the United States," Kennedy said.
GOP lawmakers rejected Kennedy's explanation that officials were relying on the best intelligence available in characterizing the attack as stemming from a protest over an anti-Islam Internet video rather than a deliberate, planned act of terrorism.
In statements immediately after the attack, neither Mr. Obama nor Clinton mentioned terrorism. And both gave credence to the notion that the attack was related to protests about the privately made video ridiculing the Muslim Prophet Muhammad.
"Some have sought to justify this vicious behavior as a response to inflammatory material posted on the Internet," Clinton said on the night of the attack. "The United States deplores any intentional effort to denigrate the religious beliefs of others. Our commitment to religious tolerance goes back to the very beginning of our nation. But let me be clear: There is never any justification for violent acts of this kind."