"We have increased our presence and our footprint and prepared for any threat that is presented by the pro-regime forces," said the spokesman, U.S. Army Colonel Ryan Dillon, referring to Iran-backed forces supporting Syrian President Bashar al-Assad.
According to Reuters:
This southeastern area of the Syrian desert, known as the Badia, has become an important front in Syria's civil war between Assad, backed by Iran and Shi'ite militias, and rebels seeking to oust him.Why is the US involved in this mess?
They are competing to capture land held by Islamic State, which is retreating as it comes under intense attack in Iraq and along Syria's Euphrates basin.
Western-backed Syrian rebels said on Wednesday that Russian jets attacked them as they tried to advance against Iran-backed militias.
U.S.-backed rebels took Tanf from Islamic State last year, and regional intelligence sources say they mean to use it as a launchpad to capture Bukamal, a town on Syria's border with Iraq and an important jihadist supply route.
The coalition's presence in Tanf, on the Damascus-Baghdad highway, was also meant to stop Iran-backed groups from opening an overland route between Iraq and Syria, the sources say.
Damascus has declared the Badia and Deir al-Zor priorities in its campaign to re-establish control over Syria, which has been shattered by six years of a war that has killed hundreds of thousands of people.