The vice president of the United States says Kurdish-led military forces should limit their movements in northern Syria or risk losing US support.
In a press conference in the Turkish capital Ankara on Wednesday, Joe Biden supported Turkey's demands that Kurdish forces, whose territorial gains have been aided by US-led airstrikes in Syria, should restrict their movements to the eastern side of the Euphrates river.
"At no point will we support the Kurdish forces if they stay to the west of the Euphrates," he said.
The Kurdish-led Syrian Democratic Forces liberated the northern Syrian town of Manbij from the Islamic State earlier this month and had started a campaign towards Jarabulus on the Turkish border.
Early on Wednesday, Turkey launched its largest known ground incursion into Syrian territory, with tanks, Syrian and Turkish ground troops and airstrikes targeting IS and Kurdish People's Protection Units (YPG) positions around Jarabulus.
Turkish Prime Minister Benali Yildirim reiterated Biden's demands and added that Washington and Ankara were in agreement on that point.
A spokesperson for Syrian based Kurdish organisation Democratic Union Party (PYD) said in an interview with Russian news outlet RIA Novosti that areas west of the Euphrates were Kurdish areas liberated by Kurds.
They added that Turkey had illegally entered into foreign territory and now was trying to implement its own conditions.
Benali said at the press conference that Turkey wished for a diplomatic and unified solution in Syria, whose civil war has raged for five years.
He reiterated that Ankara "would not allow for a Kurdish entity" to be established on Turkey's southern frontier.
