FILE - In this March 6, 2017 file photo, Director General of the International Atomic Energy Agency, IAEA, Yukiya Amano of Japan speaks in Vienna, Austria. The inspections regime put in place to closely monitor Iran’s nuclear activity is in jeopardy unless the U.S. and other nations contribute more money, the head of the U.N.'s International Atomic Energy Agency said Wednesday, March 22, 2017. (AP Photo/Ronald Zak, File)
Secretary of State Rex Tillerson stands with International Atomic Energy Agency Director General Yukiya Amano, at the State Department in Washington, Thursday, March 2, 2017, (AP Photo/Susan Walsh)
Secretary of State John F. Kerry sits between Secretary of Energy Ernest Moniz (left) and IAEA Director General Yukiya Amano during a meeting in Vienna, Austria. (Associated Press)
International Atomic Energy Agency (IAEA) Director General Yukiya Amano, of Japan, addresses the 2015 Nuclear Nonproliferation Treaty (NPT) review conference, in the United Nations General Assembly, Monday, April 27, 2015. (AP Photo/Richard Drew)