Qatar’s Emir Sheikh Tamim bin Hamad Al Thani has met President Ebrahim Raisi in Tehran as the Gulf state tries to help end a dispute between Tehran and Washington over revival of the 2015 nuclear deal.

State TV showed the arrival of the Qatari leader at Tehran’s Mehrabad Airport, where he was received by Iran’s Senior Vice President Mohammad Mokhber. The report said bilateral, regional and international issues are on agenda during the visit.

The one-day visit on Thursday came as the European Union’s coordinator for the nuclear talks, Enrique Mora, held a second day of meetings in Tehran with Iran’s chief negotiator Ali Bagheri.

Qatar, a close ally of the United States, has added the Iran nuclear dispute to the list of diplomatic efforts where it has sought to play a behind-the-scenes mediating role, and Sheikh Tamim has called for more dialogue to settle the standoff.

The trip was aimed to bring the parties to the Iran nuclear pact to “a new middle ground”, the Reuters news agency quoted an unnamed source as saying.

The stakes are high since failure to reinstate the pact could carries regional risks. Israel, Iran’s rival, has threatened military action if diplomacy collapses.

Talks in Vienna have been stalled for months, apparently over an Iranian demand that Washington lift a terrorism designation on Iran’s powerful paramilitary Islamic Revolutionary Guard Corps.

Abandoned deal

Washington unilaterally abandoned the nuclear deal with Iran under then-President Donald Trump in 2018 and re-imposed sweeping economic sanctions, prompting Iran to begin rolling back its own commitments.

President Joe Biden has said he wants the US to return to the agreement, but on and off talks on the mechanics have been stalled since March.

Under the 2015 pact, Iran curbed its sensitive uranium enrichment work, a possible pathway to nuclear arms, in return for the lifting of economic sanctions.

Unlike some of its Gulf Arab neighbours, Qatar has maintained close relations with Iran and the two countries share the world’s largest natural gas field.

Iran’s state news agency IRNA said “unfreezing Iran’s assets, cooperation in holding the 2022 World Cup, pursuing prisoner exchanges and cooperation in the field of energy” were also on the agenda of the emir’s visit.

Iran has expressed interest in hosting spectators for the Men’s Football World Cup finals in Qatar in November on its nearby resort island of Kish. It is waiving visa fees for visitors in the hope of attracting fans to the island.

Speaking in Tehran, Sheikh Tamim said those responsible for killing veteran Al Jazeera reporter Shireen Abu Akleh must be held accountable.

His comments were made during a live news conference with Raisi in Tehran. Abu Akleh suffered a gunshot wound to the head in Jenin on Wednesday. Al Jazeera, witnesses and Qatar accused Israeli troops of the killing.

Qatar hosted Raisi in February. Despite its small size, the Gulf nation plays a strategic role as a quiet mediator and negotiator in the region and internationally. Qatar’s ties with both Washington and Tehran allow Doha to relay viewpoints between the two.