European Union foreign policy chief Josep Borrell met Iran's top diplomat on Saturday after arriving in Tehran for talks on efforts to revive the 2015 Iran nuclear deal.
The surprise visit by Borrell, who arrived in the Iranian capital on Friday night, is aimed at getting the talks back on track three months after they stalled amid differences between Iran and the United States.
"Diplomacy is the only way to go back to full implementation of the deal and to reverse current tensions," Borrell tweeted.
Borrell went into a meeting with Foreign Minister Hossein Amir-Abdollahian in the morning and was expected to hold talks with other Iranian officials later in the day, said the official news agency IRNA.
The Iran nuclear deal has been hanging by a thread since 2018, when then US president Donald Trump unilaterally withdrew from the accord and began imposing crippling economic sanctions on America's arch enemy.
The administration of incumbent US President Joe Biden has sought to return to the agreement, saying it would be the best path with the Islamic republic.
The US pointman on Iran, Robert Malley, "reiterated firm US commitment to come back to the deal" over a meal with Borrell on the eve of his trip, according to the EU's coordinator for the talks, Enrique Mora.
- 'Meaningful diplomacy' -
"We remain committed to the path of meaningful diplomacy, in consultation with our European partners," Malley said later on his official Twitter account.
The talks, which began in April last year, aim to return the United States to the deal, including through lifting sanctions, while ensuring Iran's full compliance with its nuclear commitments.
The negotiations stalled in March amid differences between Tehran and Washington, notably over a demand by Iran to remove its Islamic Revolutionary Guard Corps from a US terror list.
"We are ready to conclude this agreement, and urge Iran to seize this diplomatic opportunity to conclude now, while this is still possible," a French foreign ministry spokeswoman said on Friday.
Amir-Abdollahian said on Thursday that Iran was "serious" about reaching an agreement.
"I hope we can reach the final point of the agreement in the near future with realism from the American side," he said, adding that "the nuclear negotiations train has reached difficult stops as they near the end."
The 2015 nuclear deal reached with six major powers -- Britain, China, France, Germany, Russia and the US -- gave Iran relief from sanctions in return for guarantees it could not develop an atomic weapon.
Iran has always denied wanting a nuclear arsenal.
- Cameras removed -
In April, Secretary of State Antony Blinken said the United States still believed a return to the accord was "the best way to address the nuclear challenge posed by Iran".
Blinken warned at the time that the "breakout time" for Iran to develop a nuclear bomb if it so chooses was "down to a matter of weeks" after the deal pushed it beyond a year.
The International Atomic Energy Agency's board of governors adopted a resolution this month censuring Iran for failing to adequately explain the previous discovery of traces of enriched uranium at three sites which Tehran had not declared as having hosted nuclear activities.
On the same day, June 8, Tehran said it had disconnected a number of IAEA cameras that had been monitoring its nuclear sites.
IAEA chief Rafael Grossi later confirmed 27 cameras had been disconnected, leaving about 40 still in place.
The move by Iran, he warned, could deal a "fatal blow" to the negotiations unless the UN nuclear watchdog's inspectors were given access within three to four weeks.
The visit by Borrell, his first to Tehran since February 2020, could be a determining factor in the fate of the deal.
During the talks in Vienna aimed at reviving the accord, Iran has repeatedly called for guarantees from the Biden administration that there will be no repeat of Trump's pullout.