WASHINGTON — US Secretary of State Hillary Clinton vowed Wednesday to answer lingering questions about last month's deadly attack on a US mission in Libya, seeking to counter a barrage of Republican criticism.

"There are continuing questions about what exactly happened in Benghazi on that night three weeks ago and we will not rest until we answer those questions and until we track down the terrorists who killed our people," Clinton said.

"The men and women who serve this country as diplomats deserve no less than a full and accurate accounting, wherever that leads," she told reporters, insisting that she was "committed to seeking that for them."

But Clinton warned against snap judgments, despite a growing clamor for information about the September 11 attack on the US mission in Benghazi in which the US ambassador was killed with three other Americans.

"It's essential that we go through all of the information and the entire context so that we can get a full and complete, accurate understanding of what happened," Clinton said.

"Let's establish all the facts before we jump to any conclusions, and let's do so so that we can get to the bottom of what did happen."

Four weeks before the November 6 elections the attack is a dominant theme of the campaign, as Republican opponents seek to make political capital out of it, alleging there were serious security lapses.

Republican Representative Darrell Issa, chairman of the Oversight and Government Reform Committee, has said he will call a hearing on October 10 to probe the events in Benghazi, and called on Clinton to provide answers.

Republicans have lashed Obama over the attack, raising questions about the administration's security and foreign policies.

Initially, the Obama administration insisted the Benghazi assault was a spontaneous protest against an anti-Islam film, which had sparked demonstrations the same day in Cairo when the US embassy was stormed.

But late last week, it finally acknowledged that Al-Qaeda elements may have been linked to the attack in which the Benghazi compound was gutted by fire.

Clinton urged there should be a "rigorous, careful" investigation into the attack and refused to answer a question about allegations that requests for extra security in Libya had been denied.

She has set up an inquiry into whether security measures at the consulate were properly implemented, headed by veteran diplomat Thomas Pickering, and including Admiral Mike Mullen, former chairman of the Joint Chiefs of Staff.

"I am aware too that many people are eager for answers. So am I. And no one wants the answers more than we do here at the department," Clinton said after talks with Kazakh Foreign Minister Yerlan Idrisov.

"Based on the reviews so far, we're developing a better understanding of what happened, but we have a lot of work to do to give complete and accurate responses to all the questions and statements that are swirling out there."

She added that she has asked the review to move "as quickly as possible without sacrificing accuracy. In the interim, we will provide as much accurate information to the Congress and the public along the way."

In his letter to Clinton, Issa detailed a dozen attacks or threats against US and Western staff in Benghazi in the months before the attack -- including two bomb attacks on the consulate.

One was a small explosion by a homemade bomb in April. The second blew a hole in the north gate. It was claimed by an alleged Libyan jihadist group and injured one person.