"My impression is the State Department clearly failed the Boy Scout motto of 'be prepared,'" said Senator John Barrasso, a Republican.

"They failed to anticipate what was coming because of how bad the security risk already was there. They failed to connect the dots. They didn't have adequate security leading up to the attack, and once the attack occurred, the security was woefully inadequate."

Representative Adam Schiff, a member of the House Intelligence Committee, said security was "plainly inadequate, intelligence collection needs to be improved, and our reliance on local militias was sorely misplaced." Schiff, a Democrat, added that "these are not mistakes we can afford to make again".

The House committee chairman, Representative Mike Rogers, a Republican, said the report laid bare "the massive failure of the State Department at all levels, including senior leadership, to take action to protect our government employees abroad," and complained that no one was being held accountable.

Rogers also said he was dissatisfied with the lack of progress in finding the attackers.

Lamb testified in October before the House Oversight and Government Reform Committee and defended the security measures.

"I made the best decisions I could with the information I had," Lamb said. "We had the correct number of assets in Benghazi at the time of 9/11."

She also told Representative Dan Burton, a Republican, that she rejected requests for more security in Benghazi, instead training "local Libyans and army men" to provide security, a policy in force at US diplomatic operations around the world.

The Associated Press