Iran, the United States and the European Union said Wednesday they would send representatives to Vienna amid what appears to be a last-ditch effort at reviving talks over Tehran's tattered 2015 nuclear deal with world powers.
It wasn't immediately clear if other parties to the accord would attend the surprise summit, nor if there had been any progress after a monthslong stalemate and recent fruitless round of indirect talks between Iran and the US in Doha.
