Top EU diplomat Josep Borrell on Monday held talks in the Iranian capital on a mission aimed at lowering tensions over the Islamic republic's nuclear programme.
Borrell's trip, his first to Iran since taking office, follows a spike in tensions between arch foes Washington and Tehran after the January 3 assassination in Baghdad of a top Iranian general in a US drone strike.
The two-day visit opened with a meeting with Foreign Minister Mohammad Javad Zarif, ahead of talks with President Hassan Rouhani and parliament speaker Ali Larijani.
The 2015 nuclear deal between Tehran and a group of world powers has been crumbling since US President Donald Trump withdrew from it in 2018, and Washington has since stepped up sanctions and a campaign of "maximum pressure" against Iran.
Tehran has gradually stepped back from its own commitments under the deal, while military tensions with the US brought the two countries to the brink of full-blown confrontation last month.
Borrell's mission aims "to de-escalate tensions and seek opportunities for political solutions to the current crisis," said the office of the EU's high representative for foreign affairs and security policy.
The trip will allow Borrell "to convey the EU's strong commitment to preserve" the nuclear deal, known as the Joint Comprehensive Plan of Action, and to discuss cooperation between the EU and Iran, his office said.
Iranian foreign ministry spokesman Abbas Mousavi told a press conference Monday that Tehran hoped Borrell's visit would help the European Union "understand" its situation and prompt the bloc to "show goodwill by taking serious measures".
- Accusations, denials -
Borrell said on January 24 that he had consulted the countries still in the deal -- which also include Russia and China -- and that all are determined to save the accord.
A joint commission that oversees the deal and comprises representatives of all the countries involved will meet in February, he said, without giving a precise date.
Washington accuses Tehran of seeking a nuclear weapon, which Iran has always denied.
The deal struck in Vienna between Iran and the five permanent members of the UN Security Council -- Britain, China, France, the United States and Russia -- plus Germany, offered Tehran a partial reprieve from crippling international sanctions.
In exchange, Iran agreed to drastically reduce its nuclear activities and to submit to a tailor-made inspection regime by the International Atomic Energy Agency (IAEA).
The US withdrawal from the deal and its reimposition of biting sanctions deprived Iran of anticipated economic benefits.
The renewed US sanctions have almost entirely isolated Iran from the international financial system, driven away oil buyers and plunged the country into a severe recession.
Since May 2019, Iran has progressively scaled back commitments under the agreement in response to the US sanctions and Europe's inability to circumvent them.
Iran is now producing uranium enriched beyond the 3.67 percent set by the agreement, and no longer adheres to the limit of 300 kilogrammes (660 pounds) imposed on its enriched uranium stocks.
It has also resumed research and development that was restricted under the deal.