The European Union's political director said on Wednesday that he was "quite sure" that there would be a final agreement to revive the Iran nuclear deal.
"We have made substantial progress over the last 10 days but there are still things to be worked on and we will reconvene next week and we will continue working," Enrique Mora, who is coordinating indirect talks between Iran and the United States, told reporters at the end of a fourth round of talks in Vienna.