A US military spokesman described the lull as "a loose agreement" which he hoped would solidify.
Kurdish sources say a ceasefire is in place but a Turkish-backed Syrian rebel commander rejected the term.
Turkish forces have been attacking Kurdish fighters since crossing the border last week.
Turkey is alarmed by the growing power of Kurdish forces, which have proved to be strong allies of the US-led coalition fighting IS.
"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 (IS) threat," said Col John Thomas of US Central Command.
"It's a loose agreement for at least the next couple of days and we are hoping that will solidify."
US state department spokesman John Kirby would not comment on whether a ceasefire was in place, but said the clashes had stopped "and that's the outcome that we want".
"We don't want to see them fighting each other, we want to see everybody in the coalition... focus our efforts on Daesh," he said, used another name for IS.
Turkish forces and allied factions of the rebel Free Syrian Army (FSA) forced IS out of the Syrian border city of Jarablus last Wednesday and have since pounded neighbouring villages held by the Kurdish-led, US-backed Syria Democratic Forces (SDF).
Turkey has insisted that Kurdish militia, which it regards as terrorists, retreat east across the Euphrates river.
The Jarablus Military Council, which is backed by the SFD, said a truce had been reached with Turkey "via the United states and the international coalition".
But a Turkish-backed Syrian rebel commander described it only as a "pause" in the fighting and said military operations would soon resume.
The Turkish foreign ministry would only say that it was waiting for Kurdish forces to "fulfil a promise" and retreat east of the Euphrates "as soon as possible".
Turkish presidential spokesman Ibrahim Kalin said Kurdish-led forces were "shamelessly using the war in Syria to create a de-facto terrorist state in Syria", adding: "Turkey will not allow that."
The US has welcomed a pause in fighting between Turkish and Kurdish forces in northern Syria, urging them to focus on fighting so-called Islamic State (IS).