ANKARA, Turkey – Turkey warned predominantly Kurdish Syrian fighters on Monday to "immediately" withdraw east of the Euphrates River or face more strikes by Turkish forces that crossed the border last week in Ankara's major incursion into Syria.
Pentagon, meanwhile, called on NATO ally Turkey and the predominantly Kurdish U.S.-backed fighters aligned against the Islamic State group to stop fighting each other in northern Syria. In a written statement, Pentagon press secretary Peter Cook called the clashes south of the Euphrates River town of Jarablus in Syria "unacceptable" and a source of "deep concern."
However, Kurdish-backed forces later said they will only pull back south from their current positions, in order not to put the lives of civilians in danger following attacks by Turkey-backed Syrian rebels.
The Kurdish announcement came hours after the warning by Turkey's Foreign Minister Mevlut Cavusoglu — and is unlikely to satisfy Ankara.
The sharp rhetoric — and the continued fighting — reflects the quagmire in northern Syria after Turkish tanks rolled across the border last week to help Syrian rebels seize the town of Jarablus from the Islamic State group, a move that was also aimed at deterring further advances by the Kurdish-led forces.
The fighting now pits Turkey, a NATO ally, against the Syrian Kurdish force — a U.S.-backed proxy that is the most effective ground force battling IS militants in Syria's five-year-old civil war. It leaves Washington in the tough spot of having to choose between two allies, and is likely to divert resources from the fight against IS.
Turkey's top diplomat spoke Monday as Syrian opposition groups reported that Turkish-backed Syrian rebels have captured more towns and villages in northern Syria as part of the operation named "Euphrates Shield," now in its sixth day.
Cook said the U.S. doesn't support reported Turkish airstrikes and artillery shelling of U.S.-backed Syrian Kurdish fighters — or Kurdish attacks on Turkish troops — in areas where IS fighters no longer are operating.
The United States and Turkey have called on the Syrian Kurdish People's Protection Units, or YPG, to pull back to the east side of the Euphrates, in accordance with U.S. assurances given to the Turks, and Cook said this pullback has "largely occurred."
"The YPG has to immediately cross east of the Euphrates River as they promised the United States and as they announced they would," Cavusoglu said. "If they don't, they will be a target."
Earlier this month, the Kurdish-led force known as the Syria Democratic Forces crossed the Euphrates and drove IS militants out of Manbij, a key supply hub south of Jarablus, following a costly 10-week campaign.
"The SDF have proven to be a reliable and capable force and our support for the SDF in its fight against ISIL is ongoing and will continue to do so," Cook said using an acronym to refer to IS. "They have fought hard and sacrificed to try and rid Syria of this hateful group."
Omer Celik, Turkey's minister in charge of relations with the European Union, said that "no one has the right to tell Turkey to 'fight this terror organization but don't fight that terror organization.'" Celik added that if the main Syrian Kurdish group has presence west of Euphrates, "then there will be an intervention."
Turkey's Hurriyet newspaper, in its online version, quotes Turkish Deputy Prime Minister Numan Kurtulmus as responding to the Pentagon by saying the United States should keep to its promise and use its influence on the PYD.
"The United States is aware of Turkey's sensitivities," Hurriyet quoted Kurtulmus as telling a group of journalists in Istanbul. "There is a promise made (that) the PYD will not remain west of the Euphrates. We want this issue resolved to that no conflict erupts here. We expect the United States to use its influence on the PYD."
"Turkey cannot sit and watch an attack from Syria. If the whole region reaches the hands of the PYD, Syria will be divided. We support Syria's territorial integrity," he said.
PYD leaders say they have withdrawn, but their units advise the Syrian Democratic Forces, and it is not clear if any remain west of the Euphrates.
Later Monday, the Jarablus Military Council, which is part of the SDF, said its fighters will withdraw to areas south of the Sajour river, a tributary of the Euphrates. The Sajour river is north of Manbij.
"We declare the withdrawal of our forces to south, to the Sajour River, to preserve the lives of civilians and so that they (Turks and their allies) don't have any justification to continue shelling civilians," the council's statement read.
The move is not likely to be accepted by Turkey, since Ankara wants the rebels to withdraw east of the Euphrates.
Syrian opposition activists have said that at least 35 civilians were killed in northern Syria in the Turkish-led operation so far. Turkey denied any civilians had been hit.
On Saturday, a Turkish soldier was killed by a Kurdish rocket attack, becoming the first such fatality in Turkey's ground offensive.
The Britain-based Syrian Observatory for Human Rights said the Turkey-backed rebels have captured 21 towns and villages near Jarablus from the Kurdish-dominated SDF.
The Observatory also reported clashes Monday between the rebels and IS fighters on the western edge of Jarablus. The Local Coordination Committees, an activist collective, said the rebels captured seven more villages since late Sunday.
Turkish artillery fired 61 rounds against 20 "terrorist" targets in and around Jarablus in the past 24 hours, Turkey's state-run Anadolu Agency reported.
Associated Press Writers Bassem Mroue in Beirut and Robert Burns in Washington contributed to this report.