U.S. Secretary of Defense Ash Carter speaks during the graduation and commissioning ceremony at the U.S. Naval Academy in Annapolis, Maryland U.S. May 27, 2016. REUTERS/Kevin Lamarque

U.S. Secretary of Defense Ash Carter speaks during the graduation and commissioning ceremony at the U.S. Naval Academy in Annapolis, Maryland U.S. May 27, 2016. REUTERS/Kevin Lamarque

U.S. Secretary of Defense Ash Carter speaks during the graduation and commissioning ceremony at the U.S. Naval Academy in Annapolis, Maryland U.S. May 27, 2016. REUTERS/Kevin Lamarque

June 10, 2016 10:29 AM (UTC+8)