The United States' new envoy to the coalition it leads against Daesh said on Wednesday that only 30 percent of airstrikes conducted by Russia in Syria targeted the terrorist group.
Brett McGurk said the rest of Russia's strikes hit "other armed groups", whereas the U.S.-led coalition was focused solely on Daesh.
Turkey and the West, for their part, accuse Russia of targeting moderate groups in Syria opposed to Assad, many of which are supported by Ankara and Washington.
The U.S. and its coalition allies have also said that Russia's actions target moderate opposition forces opposed to Russia's ally, Syrian President Bashar al-Assad.
Russia began carrying out airstrikes in war-torn Syria on Sept. 30. According to the Kremlin, the strikes are aimed at supporting the Assad regime against Daesh.
At least 250,000 people have been killed since the beginning of the Syrian conflict in 2011, with 7.6 million internally displaced and over four million having fled to nearby countries.