Defense Secretary Ash Carter speaks with Saudi Arabia's Deputy Crown Prince and Defense Minister Mohammed bin Salman as he arrives for the U.S.-Gulf Cooperation Council Summit in Riyadh, Saudi Arabia, April 20, 2016. Carter is visiting Saudi Arabia to help accelerate the lasting defeat of the Islamic State of Iraq and the Levant and participate in the U.S.-GCC Summit. DoD photo by Air Force Senior Master Sgt. Adrian Cadiz