Pentagon Briefing Defense Secretary Dr. Mark T. Esper and Army Gen. Mark A. Milley, chairman of the Joint Chiefs of Staff, speak to reporters at the Pentagon, Dec. 20, 2019. SHARE: Download: Full Size (0.83 MB) Tags: Milley, Chairman, Defense Secretary, Esper Credit: Marine Corps Sgt Warren Smith, DOD VIRIN: 191220-D-MG926-022.JPG Photo Gallery