Private Ihlas news agency reports they were moved to Sanliurfa province from Kilis in the west with the completion of Turkey's cross-border operation in Syria and may be used against Syrian Kurdish militants or YPG "if needed".
The US views the Kurdish-led Syrian Democratic Forces as the most effective partner to counter the Islamic State group in northern Syria, an assessment bolstered by the SDF's steady advances against the jihadists.
The U.S. -backed alliance of Kurdish and Arabic groups have now hemmed ISIS forces into the modern part of the town, alongside the reservoir of Syria's largest dam. Moreover they acted without any approval of the USA -led coalition.
Turkey views YPG as a "terrorist" organisation and an extension of the Kurdish PKK group that has waged a three-decade-long insurgency against Turkey for greater independence.
The Turkish military said the strikes were meant to prevent the PKK from sending terrorists, arms, ammunition and explosives to Turkey. Erdoğan vowed that Turkey will continue operations against the PKK and the YPG, similar to strikes earlier this week on Mt. Sinjar in northern Iraq and Syria's Mt. Karaçok. Eyewitnesses had told multiple news outlets that Turkish and YPG fighters had engaged in fighting in Darbasiyah this week, as the Turkish government confirmed airstrikes on YPG outposts throughout Syria. The Kurdish group said it lost 20 fighters and media activists in the strike, which was followed by cross-border clashes between the two sides.
On Saturday, more us troops in armored vehicles arrived in Kurdish areas, passing through the town of Qamishli, close to the border with Turkey.
Turkey has made clear it will use force to prevent the development of a Kurdish-controlled area on its Syrian doorstep.
Mr Erdogan said the sight of American flags in the convoy alongside YPG insignia had "seriously saddened" Turkey.
Video from northern Syria showed the USA patrols alongside Kurds flying the People's Protection Units flag.
"The patrols' goal is to discourage escalation and violence between two of our most trusted (counter-ISIS) partners and reinforce the USA commitment to both Turkey and the SDF in their fight against ISIS", a statement from the US -led joint command said. This concern was one of the reasons behind Ankara launching a large-scale military operation in the border region with Syria. Turkey considers members of the YPG or People's Defence Units to be terrorists whereas the U.S. considers them key allies in the fight against the Islamic State (IS).
He said he would discuss the issue at a meeting with US President Donald Trump next month.
"Let us, the USA, all these coalition powers, and Turkey, join hands to turn Raqqa into Daesh's grave", he said, using an Arabic acronym for ISIL, saying that Turkey is at present leading the "most effective campaign against ISIL".
The U.S. cooperates with YPG fighters among SDF ranks, which Ankara protests.
The People's Protection Units are distrusted by Turkish-backed anti-government forces in Syria, who say the group is an ally of President Bashar Assad's government.
"We hope that this military mobilisation is not meant to provoke our forces or for another goal linked to entering Syrian territories".