Turkey's foreign minister Mevlut Cavusoglu said his country "will not hesitate to take action to eliminate YPG/PKK terrorists" if it identifies Kurdish fighters near the border while adding that he "believed in his Russian partners". The pullout is expected to end at 18:00 on Tuesday.
Earlier this month, Kurdish forces agreed to withdraw from a 120-kilometre long, Arab-majority segment of the 440-kilometre border zone, but clashes have been reported since.
The Turkish military and its Syrian proxies attacked Kurdish forces in northeastern Syria in early October with the aim of creating a roughly 30-kilometre deep buffer zone along the frontier.
He was referring to the Kurdistan Workers' Party, which has waged a 35-year armed insurgency in Turkey's southeast and eastern regions.
The offensive was condemned by the European Union, and the U.S., which introduced sanctions against Turkey amid the clashes, but later cancelled them after Vice President Mike Pence managed to negotiate a 120-hour ceasefire, which later became permanent.
Alongside this, U.S. lawmakers passed a bill that imposes sanctions over Ankara's assault on Kurdish militia forces in northern Syria - an offensive that was made possible by the pullout of American troops.
That bipartisan measure imposes sanctions on senior Turkish officers concerned within the determination to launch the invasion and a Turkish financial institution with ties to President Recep Tayyip Erdogan, and requires the Trump Administration to penalize Turkey's procurement of a Russian-made missile-defense system.
Turkey hosts 3.6 million Syrian refugees and Erdogan has said his country plans to resettle up to 2 million of them in northeastern Syria. The Kurds have been allies of the USA military in efforts to fight Islamic State militants.
Russia, a close ally of President Bashar al-Assad, has emerged as the key foreign power in Syria, its influence further bolstered by the withdrawal of US troops from the northeast.
Asked about joint patrols planned with Russian forces in the area, Mr Akar said: "The rules of engagement, [the question of] which vehicles are to be used, the authorities and directives are to be determined".
"All Coalition military operations are de-conflicted with other forces operating in the region", said Col. Myles Caggins, a spokesman for the US -led anti-ISIS coalition in Syria, when asked about the patrol. It is the largest Syrian army deployment in the area since 2012.
The sanctions threat was "a disappointment to say the least", Turkish lawmaker Ravza Kavakci told RT, adding that "instead of working together with Turkey", Washington has chosen to support a Kurdish "terrorist group as their boots on the ground".
Turkey pounded Kurdish militia in northeast Syria for a second day on Thursday (10 October), forcing tens of thousands of people to flee and killing at least dozens of people in a cross-border assault on USA allies that has turned the Washington establishment against President Donald Trump.
Washington has begun reinforcing positions in Deir Ezzor province with extra military assets in coordination with the SDF to prevent ISIS and other actors from gaining access to oil fields in the area, a United States defense official has said.