Russian Defense Minister Sergei Shoigu met in Tehran on June 9 with the defense ministers of Iran and Syria.
Russian Deputy Defense Minister Anatoly Antonov said the trilateral talks were focused on increasing cooperation between the three countries for the fight in Syria against Islamic State (IS) militants and the Al-Qaeda linked Al- Nusra Front.
Antonov said Shoigu also had separate bilateral talks on June 9 with Syrian Defense Minister Fahd Jassem al-Freij and Iranian Defense Minister Hossein Dehghan.
Dehghan said after the talks that all three countries are determined to deliver a "decisive" battle against "all terrorist groups."
Dehghan said the goal could be achieved by "blocking or preventing" these groups from receiving political support or weapons that could enable them "to conduct wider operations."
Some factions in Syria that are considered to be moderate opposition groups by the United States, the European Union, and a Saudi-led coalition of Arab states are labeled as terrorist groups by Moscow, Tehran, and Damascus.
Iran and Russia are both key allies of Syrian President Bashar al-Assad’s regime.
Tehran has sent into Syria what it says are military advisers to support Assad's government.
Russia started launching air strikes in September to help Assad regime regain territory it had lost to both the IS militants and to Western and Saudi-backed opposition forces during Syria’s five-year civil war.