BEIRUT (AP) — Syria's military and an activist group say government forces and their allies are approaching a main water pumping station controlled by the Islamic State group in the country's north.

The government-controlled Syrian Central Military Media says troops are now just miles from the station, which supplies the northern city of Aleppo, Syria's largest, with water.

The advance is part of a days-long offensive against IS in northern Syria, backed by Russian airstrikes. Taking the water station would ease Aleppo's water shortage.

Meanwhile, Turkish, U.S. and Russian chiefs of military staff were meeting in southern Turkey on Tuesday to discuss the developments.

The Britain-based Syrian Observatory for Human Rights also confirmed the advance near the town of Deir Hafer, the Jarrah air base and the Khafseh pumping station.