Turkish and Kurdish forces in northern Syria have reached a "loose agreement" to stop fighting each other, a US defense official told AFP on Tuesday.
"In the last several hours, we have received assurance that all parties involved are going to stop shooting at each other and focus on the ISIL threat," said Colonel John Thomas, Central Command spokesman, using an acronym for the Islamic State group (IS).
"It's a loose agreement for at least the next couple of days and we are hoping that will solidify."
Thomas said the Turkish and Syrian Democratic Forces, made up largely of Kurdish fighters from the People's Protection Units (YPG), had opened communications with the United States and between each other "with the goal of limiting hostilities."
The United States is frantically trying to avert an escalation in violence between Turkish forces operating in and around the Syrian border town of Jarabulus and YPG fighters in the same region.
Both sides are backed by the United States, and Turkey is a key NATO partner. Over the weekend, clashes killed several Kurdish fighters.
It's a grim scenario for the Pentagon, which has pegged hopes of defeating IS in Syria largely on the SDF and has invested heavily in training and equipping the group.
Thomas called the agreement to stop fighting each other "encouraging."
The Pentagon says the SDF have withdrawn east of the Euphrates River under an earlier agreement to quit the contentious border region around Jarabulus.