Kerry was addressing the United Nations Security Council hours after Russian jets hit targets in Syria, apparently in support of Assad’s battle to cling to power in Damascus.

“If Russia’s recent actions and those now ongoing reflect a genuine commitment to defeat that organization then we are prepared to welcome those efforts,” Kerry said.

US forces, he added, are ready to “de-conflict” with Russian forces — communicate to avoid accidental encounters on the battlefield — “thereby increasing the miliary pressure on ISIL.”

“But we must not and will not be confused in our fight against ISIL with support for Assad,” he insisted.

“Moreover we have also made clear that we would also have grave concerns should Russia strike areas where ISIL and Al-Qaeda affiliated targets are not operating,” he said.

“Strikes of that kind would question Russia’s real intentions in fighting ISIL or protecting the Assad regime,” he warned.

Early reports of Russia’s strikes on Wednesday suggested they hit areas where other opposition groups, seen by the United States and its allies as moderates, have been fighting Assad’s forces.