United Nations Secretary-General Ban Ki-moon says he has formally invited Iran to join this week's Syrian peace talks in Geneva.
Ban told reporters on Sunday that Iranian Foreign Minister Mohammad Javad Zarif understands the basis of the talks is setting up a transitional government in Syria. That goal was set out in a 2012 Geneva conference on Syria.
The U.N. chief says Zarif has pledged that Iran will play a positive and constructive role in the new talks.
Iran has so far rejected the Geneva One declaration because a transitional government in Syria likely would exclude President Bashar al-Assad, a major Iranian ally.
But Ban said he is convinced Iran eventually will accept Geneva One.
Russia, another Syrian ally, has called for Iranian participation, while the United States has said Iran could participate from the sidelines.
The Geneva talks are scheduled to open Wednesday. Ban also has invited nine other nations that have an interest in the Syrian civil war to join the talks. He says their presence would be an important show of solidarity.
The U.N. chief also welcomed the main opposition group's decision to attend.
Syria says the issue of Assad giving up power is not up for discussion, so few experts expect the talks will reach this goal. But they say they do hope the discussions will result in increased humanitarian access and local cease-fires to make life easier for Syrian civilians.