Turkish and U.S. troops conducted their first joint ground patrol in northeastern Syria on Sunday as part of a so-called "safe zone" that Ankara has been pressing for in the volatile Kurdish-administered region.
Turkey hopes the buffer zone, which it says should be at least 30 kilometers (19 miles) deep, will keep Syrian Kurdish fighters away from its border. Turkey considers these Kurdish militias a threat, but they've also been key U.S. allies in the fight against the Islamic State group.
The presence of Turkish troops inside Kurdish-administered areas is a major development in the conflict along the border. Over the past four years, Washington has often had to play the role of arbiter, trying to forestall violence between its NATO ally Turkey and its local Syrian partners, the Kurdish-led fighters.
So far, the Kurdish-led forces have withdrawn as deep as 14 kilometers (nine miles) from the border and have removed defensive positions, sand berms and trenches.
The depth of the zone, as well as who will control it, is still being worked out.
Several Turkish armored vehicles with the country's red flag crossed into Syria where U.S. troops were waiting for them. About half a mile away, more U.S. armored vehicles flying the American flag waited for the patrol to begin. Associated Press journalists in the area around the village of Tal Abyad Sunday saw the vehicles linking up, with the U.S. vehicles leading the 12-vehicle convoy.