TEHRAN - The International Atomic Energy Agency (IAEA) confirmed on Thursday that its chief Rafael Mariano Grossi was to visit Tehran on Saturday.

The visit has raised the prospect of progress on one of the last issues blocking a revival of the 2015 nuclear deal, officially known as the Joint Comprehensive Plan of Action (JCPOA).

The visit by the UN nuclear watchdog's director general was reported overnight by the Nour News affiliated with Iran's Supreme National Security Council (SNSC) as negotiators in Vienna seek to restore U.S. and Iranian compliance with the deal.

"Director General Rafael Mariano Grossi will travel to Tehran for meetings with senior Iranian officials on Saturday. They will discuss outstanding safeguards issues with a view to address(ing) them," the IAEA said in a statement.

Tehran wants the issue of uranium traces found at several old but undeclared sites in Iran to be closed even though Western powers say that is a separate issue to the deal, which the IAEA is not a party to, several officials have told Reuters.

"If Grossi's trip could help the agency and Tehran to reach a roadmap to resolve existing safeguard issues, it can help revival of the nuclear deal in Vienna," Nour News said in its report, without citing a source.

The report of Grossi's trip coincides with the final stages of negotiators trying to salvage the 2015 deal between six world powers and Iran that imposed restrictions on Tehran's nuclear activities in exchange for the lifting of sanctions.

Former U.S. President Donald Trump pulled the United States out of the pact in 2018 and reimposed tough economic sanctions. That led Iran to breach many of the deal's restrictions in retaliatory measures. Iran lifted restrictions on its nuclear activities one year after the U.S. left the deal and the remaining members to the agreement, especially the Europeans, failed to compensate Iran for the sanctions.

Iran’s move was in accordance with paragraph 36 of the JCPOA which has provided a mechanism to resolve disputes and allows one side, under certain circumstances, to stop complying with the deal if the other side is out of compliance.

Three Iranian officials close to the talks said a wide array of sanctions, including those keeping Iran from exporting its oil and those on Leader Ayatollah Ali Khamenei and President Ebrahim Raisi, were to be removed if the 2015 pact was revived.