So-called Syria Democratic Forces enter Deir ez-Zor

The US-backed so-called Syria Democratic Forces (SDF) has reached Deir ez-Zor province for the first time as part of an offensive against ISIS, a Kurdish military source said on Tuesday.

Deir ez-Zor is mostly controlled by ISIS and the advance happens for the first time as a part of efforts to eliminate organization’s presence in Syria and liberate its de facto capital, Raqqa, north of the country.

The move aims to cut ISIS’s supply lines from Raqqa to Deir ez-Zor province, and also expands the SDF’s area of operations against ISIS.

"Military operations of the SDF are now taking place within the provincial boundaries of , from the north - so, via southern Hasaka (province)," the Kurdish military source told Reuters.

In November 2016, SDF launched an offensive called "Wrath of Euphrates" to capture Raqqa. One month into the operation, the US announced it would be sending 200 additional troops to support the fight. Earlier in February, SDF declared a new phase of the offensive aimed at forcing ISIS out of its main stronghold.