U.S. troops withdrew on Sunday from another town in Syria as Turkish-backed forces pushed deeper inside Syrian territory, seizing positions along a major highway that serves as the U.S. military’s main supply route into Syria — potentially cutting off U.S. troops further west, according to a U.S. official…

Turkish backed rebels have now set up checkpoints on the highway near Ain Issa, potentially cutting off the U.S. troops in bases to the west, in Manbij and Kobane, from the bulk of the U.S. force further east, Kurdish and U.S. officials said…

The highway is also an important conduit for the limited amounts of aid leaving northeast Syria. Aid workers said humanitarian organizations are also in the process of withdrawing staff as the fighting moves deeper into Syria.