Syria's army, backed by Russian air power, launched ground operations this week against the southern flank of a rebel zone consisting of Idlib and parts of adjacent provinces.
Turkey's Defence Minister Hulusi Akar said Syrian forces should return to territories agreed in an international deal in Kazakhstan to reduce hostilities and casualties.
"Humanitarian problems grow each day and it is increasingly showing a tendency to turn into a catastrophe," he said.
Akara also said the attacks pose a threat to the security of Turkey's observation posts in the northwest, where Turkey carries out patrols.
"We expect Russia to take effective and determined measures to make regime forces stop their attacks on the south of Idlib and immediately return to the borders set by the Astana agreement," Akara said, referring to the Kazakh capital by its previous name.On Monday, Russian Deputy Foreign Minister Sergei Vershinin said the operation was a reaction to terrorists in the area, and was being carried out "in coordination with our Turkish partners," TAS news agency reported.