The visit by Ali Bagheri, Tehran's chief nuclear negotiator, is the first to Gulf Arab states by an official of the new government of Iran's ultraconservative President Ebrahim Raisi.

Shiite Iran is the regional rival of Sunni Saudi Arabia, the powerbroker in the Gulf Cooperation Council that also includes Bahrain, Kuwait, Oman, Qatar and the UAE.

On Wednesday Bagheri, who is also Iran's deputy foreign minister, travelled to Abu Dhabi where he met Anwar Gargash, adviser to the UAE president.

The discussions focused on strengthening "ties on the basis of good neighbourliness and mutual respect" and developing economic and trade links, the official Emirati news agency WAM said.

On Thursday, Bagheri visited Kuwait where he spoke of "deep ties" between the two countries, according to the official KUNA agency.

Commenting on his tour, Bagheri said there was agreement to "open a new chapter" with the UAE and to "open new horizons" with Kuwait.

The United Arab Emirates downgraded ties with Iran in 2016 amid rivalry between its ally Saudi Arabia and the Islamic republic.

Talks to restore the 2015 nuclear deal between Iran and world powers are due to resume in Vienna on Monday, after a suspension since June.

The deal has been gradually disintegrating since former US president Donald Trump unilaterally withdrew from it in 2018.

President Joe Biden's administration says it is working to return the United States to the accord.

The Gulf Arab monarchies are said to be concerned that concessions could be made to Iran in the talks.