Rankine-Galloway said coalition aircraft would continue conducting “operations throughout Syria, targeting ISIS forces and providing air support for Coalition partner forces on the ground.”

“As a result of recent encounters involving pro-Syrian Regime and Russian forces, we have taken prudent measures to re-position aircraft over Syria so as to continue targeting ISIS forces while ensuring the safety of our aircrew given known threats in the battlespace,” Rankine-Galloway said in a statement. “In the areas of combat missions of Russian air fleet in Syrian skies, any airborne objects, including aircraft and unmanned vehicles of the [US-led] international coalition, located to the west of the Euphrates River, will be tracked by Russian ground and air defense forces as air targets,” the Russian Ministry of Defense stated. The latest spat came a day after an American F18E Super Hornet fighter jet downed on Sunday a Syrian SU-22 which was targeting areas held by a US-backed Syrian Democratic Forces (SDF), a Kurdish-Arab coalition militia fighting the Islamic State in the city of Raqqa. The United States and Russia, which has been providing an air cover for Syria’s President Bashar Assad since 2015 in his offensive against the Islamic State group, have a standing agreement that should prevent in-the-air incidents involving U.S. and Russia jets engaged in operations in Syria. The Russian defense ministry said it viewed the incident as Washington’s “deliberate failure to make good on its commitments” under the de-confliction deal.’

Russian Deputy Foreign Minister Sergei Ryabkov, in comments to Russian news agencies, compared the downing to “helping the terrorists that the U.S. is fighting against.”

“What is this, if not an act of aggression,” he asked.
After yesterday's downing of a Syrian Su-22 jet, Russia shuts down a deconfliction channel and says it will follow any aircraft west of the Euphrates as a target.