WASHINGTON

 Secretary of State John Kerry spoke to his Russian counterpart Sergey Lavrov on Wednesday to reiterate concerns about Russian military actions in Syria, a State Department spokesman said. 

John Kirby said Kerry made it clear to Lavrov that if reports of Russian military activities are true, it "could lead to greater violence and even more instability in Syria", in addition to harming the international community's efforts to end the conflict.

Wednesday’s call was the second of such communications between the two in the last week. 

The U.S. has previously expressed concerns about Russian shipments of arms to Syria, despite Moscow's assertion that the supplies to the Syrian regime are to fight Daesh. 

Russia and the U.S. have different views on fighting Daesh. The U.S. wants to destroy Daesh and replace Syrian President Bashar Assad, but Russia wants to fight only Daesh. 

Kerry said a possible Russian military buildup in Syria could "further escalate the conflict, lead to greater loss of innocent life, increase refugee flows and risk confrontation with the anti-ISIS coalition operating in Syria," the State Department said in a statement Sunday.

Kerry and Lavrov agreed to continue the discussion in New York later this month, when diplomats will meet as part of the annual UN General Assembly.

Both leaders have been in close contact following Israeli media reports that claimed Russian jets would be deployed to an air base controlled by the Syrian government, from which Russia could launch attacks against Daesh. 

The Kremlin has denied the charges.