Iran and the IAEA have reached a last minute deal to allow inspectors to service the UN agency's surveillance equipment, after Tehran restricted access earlier this year.
In a joint statement Sunday, the two sides agreed to work closely together.
Tehran will allow the IAEA to reset monitoring devices that measure the progress of Iran's nuclear program.
The IAEA's Director-General Rafael Grossi arrived in Tehran on Saturday, and met with the head of Iran's Atomic Energy Organization the following day.
Both sides called the meeting "constructive", agreeing to continue discussions at the IAEA's general conference in Vienna later this month.