UN nuclear watchdog chief Rafael Grossi will fly to Tehran this weekend for talks that may ease a standoff between Iran and the west just as it risks escalating and scuppering negotiations on reviving the Iran nuclear deal.

Three diplomats who follow the International Atomic Energy Agency closely said Grossi’s trip before next week’s meeting of the IAEA’s board of governors was confirmed. He will also meet the new head of the Atomic Energy Organisation of Iran.