Turkish Prime Minister Ahmet Davutoglu on Thursday said a ceasefire agreed between Syria’s warring parties was only valid inside Syria and was "not binding" for Turkey if its national security was threatened.

Turkish Prime Minister Ahmet Davutoglu on Thursday said a ceasefire agreed between Syria's warring parties was only valid inside Syria and was "not binding" for Turkey if its national security was threatened.

"It must be known that the ceasefire is valid in Syria," Davutoglu said in televised remarks in the central Anatolian province of Konya.

"When it is a question of Turkey's security, then the ceasefire is not binding for us," he added.

Turkey on successive days last week targeted Kurdish fighters inside Syria with artillery barrages, claiming that the army was responding to incoming fire, and had repeatedly reserved the right to open fire again.

Russia and the United States have set a deadline of midnight Damascus time (22:00 GMT) Friday for the "cessation of hostilities" between the Syrian army and the armed groups.

The deal, which marks the biggest diplomatic push yet to help end the five-year global war on Syria, excludes the so-called 'Islamic State of Iraq and the Levant' (ISIL) takfiri group and other terrorist organizations.

Davutoglu said Turkey would closely monitor how the ceasefire would be implemented, adding: "We support the ceasefire under any circumstances."

However, he noted on Thursday that if Turkey's security was concerned, "we do not get permission from anyone, we do not ask anyone but we do what's required."

"When it's a question of the security measures Turkey will take, the only place to have a say is Ankara," the premier said.

Turkey has demanded that the Syrian Kurdish Democratic Union Party (PYD) and its People's Protection Units (YPG) forces should remain outside the scope of the truce.

"To us, YPG is a terrorist organization the same as Daesh (ISIL) and (Al-Qaeda affiliate) Al-Nusra," Davutoglu said.