Josep Borrell and Mohammad Javad Zarif
Josep Borrell and Mohammad Javad ZarifReuters

Top EU diplomat Josep Borrell on Monday visited Tehran, where he held talks with Iranian officials on a mission aimed at lowering tensions over the Islamic Republic's nuclear program, AFP reports.

Borrell's trip, his first to Iran since taking office, follows a spike in tensions between Washington and Tehran after the January 3 assassination in Baghdad of top Iranian general Qassem Soleimani.

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.

Iran has gradually scaled back its compliance with the 2015 deal in response to US President Donald Trump’s withdrawal from the agreement in May of 2018.

In one of the moves, the Islamic Republic restarted uranium enrichment at the underground Fordow facility in violation of the deal.

Britain, France and Germany have attempted to save the agreement, but recently triggered the dispute mechanism in the nuclear deal that could eventually lead to reimposing UN sanctions on Iran.

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, according to AFP.

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".

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.