Romanian diplomat Cornel Feruta will head the International Atomic Energy Agency (IAEA) until member states agree on who will permanently succeed deceased Director General Yukiya Amano, the United Nations' nuclear watchdog said on Thursday. 

The IAEA announced on Monday that chief Yukiya Amano had died, leaving the agency with a leadership vacuum at a time of rising tensions between Iran and the West following Washington's decision last year to quit a 2015 international deal that curbed Tehran's nuclear program in return for an easing of economic sanctions. 

"As a consequence of the recent passing away of Director General Yukiya Amano, and in order to ensure the orderly and smooth functioning of the Agency, the Board of Governors has decided to designate Mr. Cornel Feruta as acting Director General, until a Director General assumes office," IAEA said in an online statement. 

Feruta, head-coordinator of the IAEA since 2013, has been responsible for coordinating the Agency's internal and external activities. 

He is known as a staunch supporter of the Joint Comprehensive Plan of Action (JCPOA), commonly known as the Iran Nuclear Deal, reached by Iran and the P5+1 (China, France, Germany, Russia, the United Kingdom, and the United States) in 2015, from which the U.S. unilaterally withdrew last year. 

"I think the JCPOA represents in itself a real success from a nuclear verification point of view," he said at a "Seminar for Diplomats" event at the agency's headquarters in August 2017.