"I don’t see any rift [between Russia and Iran], you know, we have discussions, you know, we have consultations with them and we want them to be involved closer in the diplomatic work," Churkin told journalists.
According to Churkin, Washington believes that Iran should be involved in diplomatic cooperation, but the current international atmosphere makes participation of particular countries "undesirable."
Iran has developed proposals on how to end the Syrian war that could potentially lead to a "breakthrough," Churkin said.
Russia is convinced that any external support for a political resolution of the Syrian conflict is irrelevant without Iran's involvement, Russian Foreign Minister Sergei Lavrov said on Thursday.
Lavrov is due to meet later in the day with top diplomats from the United States, Saudi Arabia and Turkey in Vienna for talks on a range of global issues, including the Syrian conflict.
Syria has been in a state of civil war since 2011. Forces loyal to President Bashar Assad have been fighting several opposition factions and numerous militant groups, including ISIL.
On September 30, Russia began precision airstrikes on ISIL positions in Syria at Assad's request.
Since the beginning of the air campaign, Russian Aerospace Forces have carried out some 830 strikes, killing several hundred militants and destroying dozens of command centers, and depots used by the terrorists.