Turkey has called on the US to reverse its decision to arm Syrian Kurdish Popular Protection Units (YPG) fighters battling so-called Islamic State.
President Recep Tayyip Erdogan said the fight against the jihadists should not involve "another terrorist group".
Ankara considers the YPG an extension of the banned Kurdistan Workers' Party (PKK), which has fought for Kurdish autonomy in Turkey for three decades.
Washington disagrees and insists the YPG is needed to capture IS-held Raqqa.
The YPG leads the Syrian Democratic Forces (SDF), an alliance of Kurdish and Arab militias that has driven IS militants from about 6,000 sq km (2,300 sq miles) of northern Syria over the past two years with the help of US-led coalition air strikes.
On Wednesday evening, the SDF said it had taken seized the strategically important town of Tabqa, 40km (25 miles) west of Raqqa, and its nearby dam.