Participants pose for a group photo during the world humanitarian summit in Istanbul, Turkey, May 23, 2016. (Xinhua/Anadolu Agency)
United Nations Secretary-General Ban Ki-moon (L) and Turkish President Recep Tayyip Erdogan attend the world humanitarian summit in Istanbul, Turkey, on May 23, 2016. The first world humanitarian summit opened here Monday with United Nations Secretary-General Ban Ki-moon urging governments, aid groups, the private sector and other stakeholders to act to improve the global humanitarian system. (Xinhua/Anadolu Agency)