Iran and the European Union announced on Wednesday that they would resume talks in what appears to be a last-ditch effort at reviving Tehran's tattered 2015 nuclear deal with world powers.
It wasn't immediately clear if other parties to the landmark accord would attend the surprise summit, nor if there had been any progress after a months-long fruitless round of indirect talks between Iran and the United States in Doha.
The European Union official who chairs the talks, Enrique Mora, wrote on Twitter that the negotiations would focus on the most recent draft on restoring the agreement.
Tehran also said it was dispatching nuclear negotiator Ali Bagheri Kani to the Austrian capital.
The meeting in Vienna comes after EU foreign affairs chief Josep Borrell has repeatedly pushed to break the deadlock and salvage the deal in past weeks.
“The space for additional significant compromises has been exhausted,” he recently wrote in The Financial Times.