Yukiya Amano, the serving director general of the International Atomic Energy Agency, has died, the global nuclear watchdog said on Monday.
Amano, 72, was at the helm of the agency when the five permanent members of the UN Security Council plus Germany signed the Joint Comprehensive Plan of Action with Tehran.
The longtime Japanese diplomat, who had previously served as his country's representative to the IAEA, was rumoured to be ill.
He was due to step down from his role next year due to health reasons, Japan Times reported in April.
Amano had held the position since 2009, with the term to run until 2021.
UAE Minister of State for Foreign Affairs Dr Anwar Gargash expressed his condolences on Twitter on Monday: "Deeply saddened by the passing of IAEA Director General Yukiya Amano, a dedicated leader of Atoms for Peace and a close friend of the UAE. I express my sincere condolences to his family, friends and colleagues."
Deeply saddened by the passing of @IAEAorg Director General Yukiya Amano, a dedicated leader of Atoms for Peace and a close friend of the UAE. I express my sincere condolences to his family, friends and colleagues.
— د. أنور قرقاش (@AnwarGargash) July 22, 2019
His sudden death leaves the IAEA with a void at a time when Iran has become vocal about its intention to continue enriching uranium, following the withdrawal of the US from the JCPOA and reimposition of sanctions.
The Iran nuclear deal, which was formed under the Barack Obama administration sought to restrict Tehran's regional nuclear ambitions in return for access to the global energy and financial markets.
Mr Obama's successor Donald Trump critcised the deal and said it worked in the favour of Tehran. In May last year, despite opposition from European allies, Russia and China, Mr Trump ditched the agreement and imposed restrictions on the sale of crude and condensate by Iran.
The IAEA did not reveal the cause of Amano’s death.
His deputy Mary Alice Hayward, who had served in the US government prior to her current role, is set to take over as acting director general.
The IAEA flag will fly at half-mast in tribute to Amano who replaced Egyptian diplomat Mohamed ElBaradei in 2009. The board of the IAEA is set to convene at their headquarters in Vienna in September.
Amano had been opposed to the spread of nuclear arms citing the devastation of Japanese cities Hiroshima and Nagasaki by the US in 1945 as forming his views. He steered the IAEA during challenging times, particularly after the Fukushima meltdown in Japan two years into his tenure. The disaster, the most significant since Chernobyl in 1986, turned world public opinion against nuclear power stations, with developed nations such as Germany switching off their atomic plants.
