World and regional powers including Iran met in Vienna on October 30 to discuss a political solution to Syria's civil war. Days later, Iran threatened to pull out of the next round of talks, blaming the "negative role" played by regional rival Saudi Arabia.
"Iran will be actively present in [Syria peace] talks, while announcing its standards and preserving its redlines," Ali Akbar Velayati, Khamenei's top foreign policy adviser, was quoted as saying by the Tasnim news agency. "We will support our ally, Syria, not only in defense field, but also in political arena," he added.
Iran supports Syria's President Bashar Assad against rebels backed by regional powers including Saudi Arabia, Qatar and Turkey.
Diplomats have said the next round of international talks is likely to begin later this week.