Washington's training of the new 'Border Security Force' has added to Turkish anger over US support for Kurdish fighters
US-led coalition and Syria militia building 30,000-strong border force
The US-led anti-ISIL coalition is working with its Syrian militia allies to set up a new border force of 30,000 personnel, the coalition said on Sunday, a move that has added to Turkish anger over Washington's support for Kurdish-dominated forces in Syria.
A senior Turkish official said the US's training of the new "Border Security Force" was the reason for Ankara's summoning of Washington's charge d'affaires on Wednesday last week. The official did not elaborate.
The coalition's confirmation of the Border Security Force came as Turkish president Recep Tayyip Erdogan threatened to attack the Kurdish militia-held town of Afrin in northern Syria "in the days ahead" to clear it of "terrorists".
"The slightest disturbance on the border would be the signal for us to take a step," Mr Erdogan said in a televised speech.
Afrin is controlled by the YPG, a militia considered by Ankara to be a terror group linked to the outlawed Kurdistan Workers' Party (PKK) waging an insurgency inside Turkey.
The issue is among many causing tense relations between Ankara and Washington, though Turkish officials said in November last year that president Donald Trump had told them the United States would no longer supply weapons to the YPG.
"I hope that during an Afrin operation, these powers will not make the mistake of appearing to be on the same side as a terror organisation," Mr Erdogan said in an apparent reference to the US during a rally in the northern Turkish city of Tokat.
He added he hoped Turkey "would take action together" with its allies.
The Border Security Force, whose inaugural class is currently being trained, will be deployed at the borders of the area controlled by the Syrian Democratic Forces (SDF) — an alliance of militias in northern and eastern Syria dominated by the YPG.
About half of the force will be SDF veterans, and recruiting for the other half is underway, the coalition's public affairs office said.
The force will deploy along the border with Turkey to the north, the Iraqi border to the south-east, and along the Euphrates River Valley, which broadly acts as the dividing line separating the US-backed SDF and Syrian government forces backed by Iran and Russia.
Syria's main Kurdish groups have emerged as some of the few winners of the Syrian war, and are working to entrench their autonomy over swathes of northern Syria.
Washington opposes those autonomy plans, even as it has backed the SDF, the anti-ISIL coalition's main partner in Syria.
The coalition said the Border Security Force would operate under SDF command and that around 230 individuals were currently undergoing training in its inaugural class.
"Efforts are taken to ensure individuals serve in areas close to their homes. Therefore, the ethnic composition of the force will be relative to the areas in which they serve," it said.
"More Kurds will serve in the areas in northern Syria. More Arabs will serve in areas along the Euphrates River Valley and along the border with Iraq to the south," the public affairs office said.
"The base of the new force is essentially a realignment of approximately 15,000 members of the SDF to a new mission in the Border Security Force as their actions against ISIS draw to a close."
"They will be providing border security through professionally securing checkpoints and conducting counter-IED operations," the office said, adding that coalition and SDF forces were still engaging remaining ISIL pockets in Deir Ezzor province.
IED stands for improvised explosive device.
The US has about 2,000 troops in Syria fighting ISIL, and has said it is prepared to stay in the country until it is certain of three things: that the extremist group has been defeated, that stabilisation efforts can be sustained, and that there is meaningful progress in UN-led peace talks on ending the conflict.
The Syrian government in Damascus has declared the US an illegal occupation force, and its SDF allies as "traitors". A senior Syrian Kurdish politician said last week that the US appeared in no hurry to leave Syria.