The head of the UN nuclear watchdog will visit Tehran on Monday to discuss Iran’s nuclear programme, the spokesman for Iran’s atomic agency said, as several key dates approach.

International Atomic Energy Agency (IAEA) chief Rafael Grossi had expressed concern on November 12 over the lack of contact with the Iranian government, describing it as astonishing.

He said, he had hoped to meet Iranian officials ahead of the next meeting of the IAEA’s Board of Governors, which was scheduled for November 22.

Iran responded three days later by inviting the UN nuclear chief to Tehran.

The spokesman added that Grossi will meet Foreign Minister Hossein Amir-Abdollahian and the head of Iran’s atomic agency, Mohamed Eslami.

Grossi’s last visit to Tehran was in September when he said he had technical discussions with Eslami.

Grossi’s visit comes ahead of the resumption of nuclear talks on November 29 in Vienna, stalled since June. The talks aim to restore a 2015 deal that offered Tehran relief from sanctions in exchange for major curbs on its nuclear activities.

The Vienna talks will be attended by the remaining parties to the deal — Britain, China, France, Germany, and Russia — while the US will participate in negotiations indirectly.

The US unilaterally pulled out of the deal in 2018 under the administration of President Donald Trump but talks to revive it began earlier this year.