Iran held a conference to reconcile Syria's government with opposition factions and end the country's civil war, the official IRNA news agency reported.
The report said the one-day meeting on Sunday of some 200 opposition members and Syria's National Reconciliation Minister Ali Haidar could be a step toward a future, broad-based opposition gathering.
The report did not say if any of Syria's major rebel or exile groups had attended. Most of those groups distrust Iran, a key ally of their adversary President Bashar Assad.
Iran's Foreign Minister Ali Akbar Salehi warned at the opening of the meeting that providing opposition groups with heavy arms could put the entire region at risk of "organized terrorism."
He said that arming Assad's opponents, as Damascus accuses Qatar and Saudi Arabia of doing, violates international law and principles of non-intervention in countries' domestic affairs.
Salehi reiterated Iran's traditional stance on Syria, blaming "foreign intervention and irresponsible armed groups" for the country's uprising. He said Iran supports peaceful solutions to end the crisis.
The conference is seen as a reaction to last week's meeting in Qatar in which opposition groups formed an umbrella coalition to topple Assad.
In August, Iran held a previous conference on the Syria conflict, attended by representatives of 30 countries. The Islamic Republic has supported Assad in the 20-month uprising, repeatedly accusing the West and Israel of instigating the conflicts