"Increased state support for terrorists hostile to Syria has recently presented itself in the form of naked American aggression against one of the Syrian army positions in Deir ez-Zor in favor of the interests of the [Daesh jihadist group]," Assad said, as quoted by the Syrian presidency’s Twitter account, hosting a senior Iranian diplomat.
He added that "countries hostile to Syria increase their support for terrorism as Syria succeeds in liberating territories and signing ceasefire agreements."
The airstrikes by the coalition planes near the Deir ez-Zor airport were first reported by the Syrian Army on Saturday. Later in the day, the Russian Defense Ministry confirmed the attacks, saying they killed 62 servicemen and injured 100 more.
Australia, Denmark and the United Kingdom have confirmed their participation in the airstrikes in Deir ez-Zor.
Assad emphasized the importance of support provided by Russia and Iran during Syria's war against terrorism.