Rafael Grossi, the head of the the UN nuclear agency, theIAEA arrived in Iran's capital Tehran early Saturday, as talks to revive a 2015 Iran nuclear deal have reached a crucial stage.

Tasnim news agency in Tehran said Grossi was welcomed at the airport by Behrouz Kamalvandi, spokesperson for the Atomic Energy Organization of Iran.

In a separate report, Tasnim, affiliated with the Revolutionary Guard said that contrary to Western statements, issues related to IAEA and nuclear inspection were not the only outstanding hurdles to an agreement in Vienna. The agency said three other issues unresolved and the ball is in the court of Western parties to the talks.

Western and Russian negotiators have repeatedly said in recent days that an agreement is almost complete and could be sign at any moment.

Iranian President Ebrahim Raisi said in televised remarks late on Friday that he placed hope in God and the Iranian people, and not any "economic miracle" from talks in Vienna to revive Iran's 2015 nuclear deal with world powers.

"Regarding the talks, we place our hope in God first and then... in the capacities of the people of this country, and not at all in any economic miracle that might arise from Vienna," Raisi said. "We do seek and will continue to work towards the lifting of sanctions, more importantly neutralizing them."