Nearly five months after the attack on the U.S. Consulate in Benghazi, Libya, Defense Secretary Leon Panetta will testify to Congress on Thursday about the military's response.

Mr. Panetta will be joined by Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, and both will appear before the Senate Armed Services Committee.

Mr. Panetta is leaving the administration once his replacement is confirmed, and President Obama has tapped former Sen. Chuck Hagel to fill the slot — though Mr. Hagel is facing stiff opposition from Republicans.