BRUSSELS 

Nuclear talks in Vienna can now continue with Iran after a "very profitable" visit to Tehran by the chief EU negotiator, the bloc's foreign policy chief said on Friday.

"There is the perspective of reaching a final agreement" on bringing Iran nuclear talks back on track and ensuring full compliance with the treaty, Josep Borrell told journalists ahead of a meeting of G7 foreign affairs ministers in Weissenhaus, northern Germany.

He said the trip by Enrique Mora, the EU's chief negotiator on the Iran nuclear deal and deputy secretary-general of the EU diplomatic service, to Tehran was "very much profitable" and "has gotten better (results) than expected."

"The negotiations were stalled and now they have been reopened," he added.

Mora traveled on Tuesday to Tehran to hold talks with the Iranian deputy foreign minister and lead nuclear negotiator Bagheri Kani and other officials on resuming negotiations between Iran and the other parties to the Iran nuclear deal.

He left the Iranian capital on Thursday night.

EU diplomats have been working to get Iran and the US back to the negotiating table since Washington withdrew from the agreement in 2018 and Tehran stepped back from its commitments under the treaty.

Under EU chairmanship, representatives from Iran, China, Russia, France, the UK, and Germany negotiated for months in the Austrian capital of Vienna to ensure full compliance and bring the US back to the deal.

The Iran nuclear deal -- officially named the Joint Comprehensive Plan of Action (JCPOA) -- was signed in 2015 by Iran, the US, China, Russia, France, the UK, Germany, and the EU.

Under the agreement, Tehran has committed to limit its nuclear activity to civilian purposes and in return, world powers agreed to drop their economic sanctions against the country.

The US, under former President Donald Trump, unilaterally withdrew from the agreement in 2018 and re-imposed sanctions on Iran, prompting Tehran to stop complying with the nuclear deal.