Russian President Vladimir Putin says it's impossible to defeat the Islamic State group without cooperating with the Syrian government.
Putin made the remarks in Tajikistan on September 15 at a meeting of a Moscow-dominated security alliance of former Soviet republics.
Putin said Moscow had provided military assistance to President Bashar al-Assad's government and will continue to do so.
He dismissed allegations that Moscow's support for Assad has sparked a flow of refugees.
Putin said that without Russia's support for Assad's regime the number of Syrian refugees heading to Europe would have been even bigger.
The remarks come amid emerging reports of a growing Russian military presence in Syria.
The Pentagon and U.S. State Department said on September 14 that Russia's recent activity near the Syrian city of Latakia suggested Moscow plans to establish a "forward air-operating base” there.
Earlier on September 15, Kremlin spokesman Dmitry Peskov said that dialogue between Moscow and Washington on solving the Syria crisis was indispensable.