Turkey’s President Recep Tayyip Erdogan said on Tuesday that this country's armed forces had largely completed their military mission in Syria's northwestern Idlib province.
As he was hailing its completion, he pointed out that control of Syria's Afrin region remained an issue.
Afrin is under the control of the YPG, which is the armed wing of the PYD, which Turkey says is simply the Syrian branch of the PKK.
Speaking to his ruling Justice and Development (AK) Party's parliamentary group, President Recep Tayyip Erdogan said, "The operation in Idlib was largely completed."
"The Afrin issue is ahead of us, all of these matters pose threats to us, and we are determined to tackle issues in every field that poses threat to our country. As I said before, we can suddenly come one night, we can suddenly hit one night," Erdogan said.
TRT World'sSara Firth reports from the Turkey-Syria border.
The Idlib mission came about as a result of an agreement in September to establish a fourth de-escalation zone in Syria that largely coincides with the borders of the country's Idlib province.
Turkey will establish more than 10 observation posts inside Idlib province while the guarantor countries will create a peacekeeping force to reduce the chance of conflict under the Astana deal.
As per the deal, the three countries will set up four de-escalation zones in Syria, mainly in opposition-held areas which have been facing in-fighting between rival Syrian opposition groups who are battling each other for control, as well as fighting the Syrian regime.
This is the second time Turkey has entered Syria. The first was in 2016 during Operation Euphrates Shield.
After crossing the frontier, Turkish troops were initially deployed near the YPG-controlled Afrin.
The PKK launched its armed campaign against the Turkish state in 1984 and has killed some 40,000 people since then. It is recognised as a terrorist group by the EU, Turkey and the US.
While the Turkish military has been tasked with establishing observation posts in central Idlib, Russia has been tasked with doing the same in outlying areas.
