International Atomic Energy Agency (IAEA) Director General Rafael Grossi addresses the media at the IAEA headquarters, amid the coronavirus disease (COVID-19) pandemic, in Vienna, Austria May 24, 2021. Photo: REUTERS/Lisi Niesner The head of the International Atomic Energy Agency will visit Tehran on Saturday, the agency confirmed on Thursday, raising the prospect of progress on one of the last thorny issues blocking a revival of the 2015 Iran nuclear deal. The visit by the UN nuclear watchdog’s director general was reported overnight by the Nournews news agency affiliated with Iran’s top security body as negotiators in Vienna seek to restore...