Turkey's National Security Council says the country will respond immediately to any threats that could harm the country or its citizens emanating from western Syria, adding it would not allow the formation of a "terrorist army" along its borders.
Turkey's top civil and military leadership said on Wednesday it will take "immediate" and "resolute" steps to protect the nation from any threats coming from western Syria.
Ankara has been infuriated with comments by the US-led coalition in northeastern Syria that it was working with the YPG-led SDF to set up a new 30,000-strong border force.
The YPG spearheads the SDF and is the armed wing of the PYD which is considered by Turkey as the Syrian offshoot of the PKK.
The PKK is listed as a terrorist organisation by Turkey, the US and the EU.
After a meeting in Ankara, Turkey's National Security Council said, "Necessary steps would be taken immediately and resolutely to defeat any threat against Turkey from western Syria in the first stage."
The statement added that necessary steps will be taken to secure the life and property of the local community, and strengthen Turkey's border with Syria.
The council said, "The establishment of a terror corridor and the formation of a terrorist army across the border will not be allowed."
The meeting, chaired by the President Recep Tayyip Erdogan, lasted more than four hours.
On Monday, with relations between the NATO allies stretched close to breaking point, Erdogan threatened to "strangle" the planned US-backed force in Syria "before it's even born".
Erdogan has also threatened military action against the region of Afrin, to the west of the area where the border force is planned.
TRT World's Andrew Hopkins reports from Ankara.
Rejection of US plan
The council also rejected the US plan to establish a 30,000-strong border security force in Syria, manned by the SDF, an alliance of militants dominated by the YPG who fought against Daesh with Washington's backing.
"It is regrettable that a state, which is part of NATO and our ally in bilateral relations, declares the terrorists as its partner and provides them with weapons, without any concern for our safety," the statement said.
“Weapons, tools and materials given to PYD/PKK – YPG terrorist group must be collected without delay,” it said, adding that the fight against Daesh has been completed on a large scale.
National Security Council Convenes at the Presidential Complex https://t.co/NGMMDfXZwm— Turkish Presidency (@trpresidency) January 17, 2018
As the council met, a Reuters reporter witnessed the Turkish army deploying nine tanks to a military base just outside the city of Hatay, near the border with Afrin.
That followed earlier reports of a military buildup in the area.
The council also advised the government to extend the country's state of emergency, a proposal which was later submitted to the Grand National Assembly of Turkey by the Cabinet.
Following the council meeting, a Cabinet meeting, also chaired by Erdogan, began at 0530GMT and lasted an hour.
“Nobody should expect Turkey to be patient any more,” Turkish Deputy Prime Minister Bekir Bozdag said over US arming of YPG, after the Cabinet meeting.
He reiterated that Turkey is determined to take necessary steps regarding the issue.
Turkey has long protested US support for the YPG, while Washington has called it a "reliable ally" in its fight against Daesh in Syria.
Since the mid-1980s, the PKK has waged a wide-ranging terror campaign against the Turkish state, in which an estimated 40,000 people have been killed.