Published: Jun 12, 2013 11:25 PM EDT

WASHINGTON (AP) - The chairman of the Joint Chiefs of Staff said Wednesday that four members of Army special forces in Tripoli were never told to stand down after last year's deadly assault on the U.S. diplomatic mission in Benghazi, Libya, disputing a former top diplomat's claim that the unit might have helped Americans under siege.
    
Army Gen. Martin Dempsey said timing and the need for the unit to help with casualties from Benghazi resulted in orders for the special forces to remain in Tripoli. Four Americans, including U.S. Ambassador Chris Stevens, died in two separate attacks several hours apart on the night of Sept. 11.
    
Gregory Hicks, a former diplomat in Tripoli at the time of the attack, told a House panel last month that the unit was told to stand down.
    
Dempsey said that was not the case.
    
"They weren't told to stand down. A 'stand down' means don't do anything," he said. "They were told that the mission they were asked to perform was not in Benghazi, but was at Tripoli airport."