Defense Secretary Leon Panetta says it is clear that terrorists were behind the deadly attack on the U.S. Consulate in eastern Libya.

Asked at a Pentagon news conference about the Sept. 11 attack, Panetta said there is no question that it was planned and carried out by terrorists, but he said it is not yet clear what specific group was involved.

Asked how long it took him to come to the conclusion that it was terrorism, Panetta said it took "a while," but he was not more specific.

Addressing the same topic, Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, said that prior to the attack there was some intelligence about security threats in Libya, but it was not specific to the U.S. Consulate.