United Nations, October 1 (RHC)-- U.S. Secretary of State John Kerry has warned Russian Foreign Minister Sergei Lavrov that Russian airstrikes in Syria could escalate the years-long conflict in the Arab country, a senior American official says.

The official, speaking on condition of anonymity, said Kerry told Lavrov, who is in New York for the UN General Assembly meeting, that the Russian move is against efforts of "deconfliction" and is unhelpful. The top U.S. diplomat "conveyed the message that we will not be altering our operations and that this announcement by the Russians runs counter to their stated efforts of deconfliction and is not helpful to that effort, and again made clear that the deconfliction discussions need to begin immediately," the official said.

Kerry’s warning came shortly after Russia carried out its first airstrikes in Syria against Daesh (ISIL) terrorists, according to a senior American official. Moscow carried out the mission on Wednesday near the city of Homs, CNN reported quoting the senior unmanned official.

In response, State Department spokesman John Kirby said U.S. and its international coalition partners would continue their airstrikes in Syria, despite the fact that Russian diplomats sent an official demarche ordering U.S. planes out of Syria.