The former commander of a four-member Army special forces unit in Tripoli, Libya, says he was never told to stand down during last year's deadly assault on the U.S. diplomatic mission in Benghazi.

Lt. Col. S.E. Gibson told the House Armed Services Committee on Wednesday that senior officials told him to remain in Tripoli to defend Americans there in the event of additional attacks and to help survivors.

Gibson's testimony in a closed session with the panel disputes a claim by a former top diplomat in Libya. The Republican-led committee released a summary of its classified briefing with military officials.

Four Americans, including Ambassador Chris Stevens, were killed in the attack last September. Republicans have accused the Obama administration of misleading the public about the cause of the terrorist incident.