The United Nations invited Iran to join this week's international conference on the future of Syria after Tehran said it would accept a transitional government away from Syrian President Bashar Assad, Secretary General Ban Ki Moon said Sunday.
The U.S. had opposed Iran's participation as long as it rejected a 2012 international agreement in Geneva calling for a new government in Damascus.
Ban told reporters Sunday that after "intensive" discussions, Iranian Foreign Minister Mohammad Javad Zarif agreed to attend the conference — called "Geneva II," even though it's actually convening in Montreux — and promised that Iran would play "a positive and constructive role."
The Geneva communique issued in 2012 called for a "Syrian-led political process leading to a transition that meets the legitimate aspirations of the Syrian people" — which would almost certainly freeze out Assad, Iran's close ally.
Iran had previously said it wouldn't accept any "preconditions" for its participation. But Sunday, Ban said Zarif had concurred "that the goal of the negotiations is to establish, by mutual consent, a transitional governing body with full executive powers."
"They welcome this Geneva communique," Ban said.
As recently as Saturday, Zarif's deputy, Hossein Amir Abdollahian, told a visiting French official that this week's conference shouldn't do anything that would strengthen the hand of the militant fighters seeking Assad's overthrow, the Iranian news agency ISNA reported.
Iran's revised position came just a day after the Syrian National Coalition, the main Western-backed group battling Assad, agreed Saturday to take part in the peace talks — a decision U.S. Secretary of State John Kerry welcomed as a "courageous" move "in the interests of all the Syrian people who have suffered so horribly under the brutality of the Assad regime and a civil war without end."
Ali Fateh of NBC News contributed to this report.