Yukiya Amano, the International Atomic Energy Agency's director general, who has been in poor health for some time, has died at 72, the IAEA announced Monday.
The Secretariat did not give a cause of death for Amano, or say when he died. The agency said he was planning to write soon to the agency's board of governors announcing his decision to step down. It released part of that letter, in which Amano praised the agency for delivering "concrete results to achieve the objective of 'Atoms for Peace and Development' plan."
He added that he was "very proud of our achievements and grateful" to IAEA member states and agency staff.
The IAEA said its flag will be lowered to half-mast.
According to the agency's biography, Amano was Japan's representative to the agency from 2005 until his election as director general in July 2009, including a stint as chair of its board of governors from 2005-2006. He had extensive experience in disarmament and non-proliferation diplomacy, as well as nuclear energy issues, and assumed his duties as IAEA director general on Dec. 1, 2009.
A graduate of the Tokyo University Faculty of Law, Amano joined the Japanese Foreign Ministry in 1972 and was posted to jobs in Belgium, France, Laos, Switzerland, and the United States.
At the Foreign Ministry, Amano was chief of the Disarmament, Non-Proliferation and Science Department from 2002 until 2005. He previously served as a governmental expert on the UN Panel on Missiles and on the UN Expert Group on Disarmament and Non-Proliferation Education.
Amano contributed to the 1995, 2000 and 2005 Nuclear Non-proliferation Treaty Review Conferences, and he chaired the 2007 Preparatory Committee for the 2010 Nuclear Non-proliferation Treaty Review Conference.
Amano was reappointed as IAEA chief in 2017 to a third four-year term. His term had been due to run until Nov. 30, 2021, but diplomats said last week he was planning to step down early, in March next year, due to an unspecified illness.
The IAEA's responsibilities include policing restrictions on Iran's nuclear activities under Tehran's 2015 deal with world powers. Amano often emphasized that his agency's work is technical, not political, but the US decision to quit the 2015 deal has added to already considerable political pressures on him and his agency. That decision has triggered a growing standoff between Tehran and Washington, which has reimposed economic sanctions on Iran.