By Sarah N. Lynch and Daren Butler
WASHINGTON/ISTANBUL (Reuters) - The United States said on Sunday it is poised to withdraw some 1,000 troops from northern Syria after learning that Turkey planned to extend a military incursion further south and west than originally planned.
Another consideration in the decision, U.S. Defense Secretary Mark Esper indicated, was that Washington's Kurdish-led ally, the Syrian Democratic Forces (SDF), were looking to make a deal with Russia to counter the Turkish offensive.
On the fifth day of Turkey's offensive against Kurdish militias in northern Syria pursued despite international condemnation, Turkish-led forces appeared to have seized control of the Syrian border town of Tel Abyad, a Reuters witness said.
Turkey also said Turkish and allied Syrian rebel forces had seized a highway some 30-35 km (18-22 miles) into Syrian territory, which would sever a major artery linking the Kurdish-run regions of war-torn Syria's north.
An SDF official said clashes were going on along the road.
Turkey's offensive aims to neutralise the Kurdish YPG militia, the main component of the SDF and seen by Ankara as a terrorist group aligned with Kurdish insurgents in Turkey. But the SDF has also been Washington's key regional ally in dismantling Islamic State's so-called "caliphate" in Syria.
Ankara's stated broader aim is to carve out a "safe zone" inside Syria to resettle many of the 3.6 million Syrian war refugees it is hosting. President Tayyip Erdogan has threatened to send them to Europe if the EU does not back his assault.
But the Turkish incursion has raised international alarm over large-scale displacements of civilians and, amidst the upheaval, the possibility of Islamic State militants escaping from prisons run by the Kurdish-led authorities.
Women affiliated with Islamic State militants and their children fled en masse from a camp where they were being held in northern Syria on Sunday after shelling by Turkish forces, the region's Kurdish-led administration said.
Turkey now faces threats of possible sanctions from NATO ally the United States unless it calls off the incursion. Two other NATO allies, Germany and France, have suspended arms exports to Turkey. For its part, the Arab League has denounced the Turkish offensive as an "invasion of Arab land."
Sunday's word of the planned U.S. troop evacuation came after U.S. President Donald Trump abruptly shifted policy and withdrew a smaller number of U.S. troops deployed to support Kurdish forces in the fight against Islamic State.
That decision in turn helped open the door for Turkey to launch its offensive against the Kurdish-led SDF.
"In the last 24 hours, we learned that (the Turks) likely intend to extend their attack further south than originally planned, and to the west," Esper said in a pre-taped interview with CBS.
"We also have learned in the last 24 hours that the...SDF are looking to cut a deal, if you will, with the Syrians and the Russians to counterattack against the Turks in the north."
Esper called the situation "untenable" for U.S. forces, saying that he spoke with Trump last night, and that the president directed the U.S. military to "begin a deliberate withdrawal of forces from northern Syria".
ISLAMIC STATE-AFFILIATED FOREIGNERS FLEE CAMP
The SDF hold large swathes of northern Syria that were once part of Islamic State's jihadist "caliphate". The SDF has been keeping thousands of IS jihadists in jail and tens of thousands of their family members in camps.
But this weekend, 785 Islamic State-affiliated foreigners escaped the camp at Ain Issa, the region's Kurdish-led administration said in a statement.
The Syrian Observatory for Human Rights, citing sources in the camp, said around 100 people had escaped.
In apparent reference to Turkish-backed rebels, the Kurdish-led administration said "mercenaries" attacked the camp where "Daesh elements" - a reference to Islamic State - in turn attacked camp guards and opened the gates.
SDF official Marvan Qamishlo told Reuters there were not have enough guards for the camp, which is north of Raqqa and about 30 km (20 miles) south of the Turkish border.
"The guarding is very weak now," he said, adding there were now just 60-70 security personnel at the camp compared with a normal level of no less than 700 in the camp of 12,000 people.
(GRAPHIC: Where Kurds live - https://fingfx.thomsonreuters.com/gfx/editorcharts/SYRIA-SECURITY-TURKEY-USA/0H001QXBW8SM/KURDS.jpg)
(GRAPHIC: Turkey hits Kurdish militia targets - https://graphics.reuters.com/SYRIA-SECURITY-TURKEY-USA/0100B2G11PV/index.html)