The Kremlin said on Friday it was Turkey's responsibility to stop rebels in Syria's Idlib province from firing on civilian and Russian targets, signaling it would continue to back a Syrian government offensive there despite Ankara's protests.
The month-long offensive, the biggest escalation of the war between President Bashar al-Assad and his insurgent enemies since last summer, has raised fears of a humanitarian crisis as thousands of people shelter from air strikes at the Turkish border.
Turkish President Tayyip Erdogan told his Russian counterpart Vladimir Putin late on Thursday that he wanted a ceasefire in Idlib to prevent more civilian deaths and a refugee influx to Turkey.
Erdogan also told Putin by phone that Syria needed a political solution, Erdogan's office said in a statement.
The Turkish leader has repeatedly complained to Moscow about a Russian-backed Syrian government offensive in the rebel-held northwest, the last significant rebel stronghold.
Syrians uprooted by the fighting protested on Friday at the Atmeh crossing into Turkey, calling for an end to the strikes and for Ankara to open the frontier, which it refuses to do.