WASHINGTON, DC - APRIL 1: (AFP OUT) U.S. President Barack Obama (C) speaks as Xi Jinping, China's president (R), and Francois Hollande, France's president (L), listen during a P5+1 multilateral meeting at the Nuclear Security Summit on April 1, 2016 in Washington, D.C. After a spate of terrorist attacks from Europe to Africa, Obama is rallying international support during the summit for an effort to keep Islamic State and similar groups from obtaining nuclear material and other weapons of mass destruction. (Photo By Andrew Harrer/Pool/Getty Images)
