MOSCOW (AP) — The top diplomats of Russia and the United States have focused on the Syrian crisis in a phone call.

The Russian Foreign Ministry says Foreign Minister Sergey Lavrov and U.S. Secretary of State Rex Tillerson talked Monday about the need to secure a cease-fire in Syria, fight extremist groups and to prevent the use of chemical weapons.

It added that Lavrov "urged Washington to take steps to prevent provocations against Syrian government forces battling terrorists."

Moscow reacted angrily when the U.S. downed a Syrian jet last week after it dropped bombs near the U.S.-backed Syrian Democratic Forces conducting operations against the Islamic State group.

Russia warned its military would track aircraft from the U.S.-led coalition as potential targets over Syria and suspended a hotline intended to avoid mid-air incidents.