The head of the International Atomic Energy Agency, Rafael Grossi, is planning to visit Iran for the first time.
Diplomatic sources say IAEA Director General Rafael Grossi hopes to visit Tehran as early as next week to hold talks with senior Iranian officials.
He is expected to ask for Iran's cooperation over the IAEA's inspections of two facilities where the country is suspected of storing undeclared nuclear material.
The UN nuclear watchdog's board of governors adopted a resolution in June calling on Iran to give inspectors access to the two sites. The resolution was proposed by Britain, France and Germany.
The United States is maintaining his call to put pressure on Iran. Secretary of State Mike Pompeo met with Grossi earlier this month to discuss the need for Iran to respond to the IAEA's request.
The IAEA plans to release its updated report on Iran's nuclear program in early September, ahead of a board of governors meeting in the middle of the month. The Iranian issue is expected to be the main focus in the meeting.
Grossi's planned visit to Iran follows a visit by his senior staff in charge of inspections in mid-August.
Grossi is also expected to talk with Iranian officials about a nuclear facility in Natanz in central Iran, where a fire broke out last month.