A House Intelligence Committee is holding closed oversight hearings today examining the attack at the U.S. Consulate in Benghazi on Sept. 11, 2012, that killed U.S. ambassador to Libya Christopher Stevens and three other Americans.

Senator John McCain, centre, Senator Kelly Ayotte, left, and Senator Lindsey Graham, right, on Wednesday said UN ambassador Susan Rice intentionally misled Americans on the Benghazi attack. (J. Scott Applewhite/Associated Press)

The hearings on Capitol Hill will focus on the "intelligence collection and threat reporting relating to Libya and other Middle East countries prior to the Sept. 11 attack, how and when that information was disseminated and what actions were taken in response," the committee said in a statement. They will also examine the level and adequacy of security at the State Department and other U.S. facilities in the region, it added.

High-profile officials, including the director of the FBI, will testify before congressional committees about what they know of the attack.

On Friday, the committee is expected to hear from David Petraeus, the retired four-star general who resigned as head of the CIA last week after admitting to an extramarital affair with his biographer.

Committee officials planned to limit the subject of that hearing to Libya, ruling out questioning about the affair with Broadwell and any potential national security implications.

'He didn't tell the truth'

Questions about the handling of that attack — and when the Obama administration knew it was a terror attack — was a key and contentious issue during the U.S. election, and sparked verbal clashes between the president and Republican Senator John McCain on Wednesday.

"He didn't tell the truth to the American people at one time or another," he said to reporters.

McCain and fellow Republican Lindsay Graham accused the U.S. ambassador to the UN, Susan Rice, of knowing that it was a terror attack and not a demonstration that turned violent, which she called it days later.

During a press conference in Capitol Hill, McCain and Graham said Rice intentionally misled the country, and if the president nominated her as the his Secretary of State, they would attempt to stop it.

President Barack Obama fiercely defended UN ambassador Susan Rice's handling of the Benghazi attack during a news conference at the White House on Wednesday. (Charles Dharapak/Associated Press)

"I think she knew better, and if she didn't know better, she shouldn't be the voice of America," Graham said.

President Barack Obama, in his first media conference since his re-election last week, fiercely defended Rice.

"She gave her best understanding of the intelligence that had been provided to her … To besmirch her reputation is outrageous," he said.

2nd hearing held Thursday

In another set of hearings held by the House committee on foreign affairs that also began Thursday, and will examine what could have been done to prevent the Benghazi attack, committee members offered their condolences to the families of the four who died, and called for answers and accountability.

“I think we need to have a real honest explanation of what happened," said Republican Jean Schmidt. The hearing is an important step toward achieving accountability, said Republican David Rivera.

Michael Courts, acting director of International Affairs and Trade, was the first witness to provide testimony, which was primarily based on a Government Accountability Office report. The 2009 report found a number of challenges including staffing shortages and language gaps.

The committee grilled Courts on embassy security. Near the end of his questioning, Courts said that the state did not fulfil one of the report recommendations: conducting a strategic review of the Bureau of Diplomatic Security, which should have addressed "key human capital and operational challenges."

Three other witnesses appeared Thursday, including the president of the American Academy of Diplomacy.

With files from The Associated Press