They added that while intelligence officials indicated early on that extremists were involved in the assault, only later were officials able to confirm that the attack was not generated by a protest over the film.
Arizona Sen. John McCain and other Republicans insist that if the Obama administration didn't know enough about the attack to discuss it clearly in the days that followed, it should have. They also say the response to the attack has been too muted to send a deterrent message to terrorists.
The officials' description Thursday of the attack provided details about a second CIA security team in Tripoli that quickly chartered a plane and flew to Benghazi but got stuck at the airport. By then, however, the first team had gotten the State Department staff out of the consulate and back to the CIA annex.
While the U.S. military was at a heightened state of alert because of 9/11, there were no American forces poised and ready to move immediately into Benghazi when the attack began.
The Pentagon would not send forces or aircraft into Libya — a sovereign nation — without a request from the State Department and the knowledge or consent of the host country. And Defense Secretary Leon Panetta has said the information coming in was too jumbled to risk U.S. troops.
AP National Security writer Robert Burns contributed to this report.
Lolita C. Baldor can be followed on Twitter at http://twitter.com/lbaldor