"I take responsibility... I take this very personally," Clinton told the CNN in Lima, the capital of Peru.
"So we're going to get to the bottom of it, and then we're going to do everything we can to work to prevent it from happening again, and then we're going to work to bring whoever did this to us to justice," she said.
Clinton was responding to questions on terrorist attack on the Benghazi Consulate last month that left US Ambassador to Libya Chris Stevens and three others dead.
The Obama Administration initially attributed this to an anti-Islam video that resulted in an instant protest. Later, the administration dubbed it as a terrorist attack.
Last week, Vice President Joe Biden said the White House did not know of requests to enhance security at Benghazi, contradicting testimony by State Department employees that requests had been made and rejected.
"In the wake of an attack like this, in the fog of war, there's always going to be confusion. I think it is absolutely fair to say that everyone had the same intelligence. Everyone who spoke tried to give the information that they had. As time has gone on, that information has changed. We've gotten more detail, but that's not surprising. That always happens," Clinton told the CNN.
"What I want to avoid is some kind of political gotcha or blame game. I know that we're very close to an election. I want to just take a step back here and say from my own experience, we are at our best as Americans when we pull together. I've done that with Democratic presidents and Republican presidents," Clinton said.
Top Republican Senators were quick to describe Clinton's remark as a "laudable gesture" but said President Barack Obama also bears responsibility for this portrayal of the attack.