The Syrian presidency said Moscow will keep up its support for the regime's "anti-terrorist" battle, following the surprise announcement Monday of a pullout of Russian forces from the war-torn country, AFP reports.

"The Syrian and Russian parties agreed in a telephone call between Presidents Bashar al-Assad and (Russia's) Vladimir Putin to reduce the number of Russian air force personnel in Syria," the president's office said on its Facebook page.

"The Russian side said it will continue to support Syria in its battle against terrorism," it said.