Hossein Amir-Abdollahian, who travelled to Riyadh on Thursday, would hold talks with the Saudi Crown Prince in Jeddah, Iranian and Saudi officials said, after extending what had been scheduled to be a one-day visit.

Shia Muslim-majority Iran and Sunni-ruled Saudi broke off ties in 2016, but they agreed to restore diplomatic relations in a Chinese-brokered deal in March.

The announcement sparked optimism as the two regional heavyweights have backed opposing sides in conflict zones across the Middle East for years, including in Yemen, Saudi's impoverished neighbour.

On Thursday, Amir-Abdollahian said ties "are progressing in the right direction" as he appeared in front of the media with his Saudi counterpart, Prince Faisal bin Farhan.

His visit would "be a prelude to the meeting of the heads of the two countries", he said, without specifying when Iran's President Ebrahim Raisi would travel to Saudi Arabia at King Salman's invitation.

Iran's top diplomat hailed economic and security cooperation between the two countries, but announced no new agreements. He was accompanied by Iran's new ambassador to Saudi, Alireza Enayati.

"We are sure that these meetings and cooperation will help the unity of the Islamic world," Amir-Abdollahian added, proposing a "regional dialogue" without giving details.

Since the March deal, Saudi Arabia has ramped up a push for peace in Yemen, holding direct talks with Huthi leaders in the Yemeni capital Sanaa, and championed the return of key Iran ally Syria to the Arab League.