A clash between Syrian and Turkish troops edged a step closer Monday as Bashar al-Assad’s forces reached the Turkish border, according to Syria’s state news agency. The move came hours after Syrian Kurdish forces—the previous allies of the United States—reached a deal with Syria to help them fight Turkey’s invasion in a major shift of alliances in the region. The news agency said the Syrian army had moved into the town of Tal Tamr, about 12 miles from the Turkish border. The agency said the troops would “confront the Turkish aggression” and photos showed several vehicles and a small number of troops in the town. The U.S. edged toward a full military withdrawal from Syria on Sunday, with Defense Secretary Mark Esper saying President Trump had directed U.S. troops in northern Syria to begin pulling out “as safely and quickly as possible.” He added: “We have American forces likely caught between two opposing advancing armies and it’s a very untenable situation.”