Erdogan views the YPG, which controls part of Syria's border with Turkey, as an extension of the Kurdish PKK, a Marxist insurgent group which has operated in Turkey for decades and is also considered a terrorist organization by the US and EU.
In recent weeks, there have been exchanges of rocket and artillery fire at Syria's northwestern border between Turkish forces and YPG fighters.
Having reinforced the border with more tanks and artillery, Erdogan told a crowd in Turkey's eastern town of Malatya on Saturday, "We will not leave the separatist organization in peace in both Iraq and Syria."
Ankara has made no official announcement about a military operation in northern Syria, but Turkish journalist and political analyst Bora Bayraktar told Sputnik that Turkey seems to be preparing to launch a military operation in the Afrin region of northwestern Syria, which is under the control of YPG militia.
"In particular, there is constant military activity in the region of the Turkish town of Kilis and the Syrian town of Azaz. At certain times of the evening, there is the sound of artillery fire coming from Afrin. Local sources told us that Turkey is preparing for a limited ground operation. The same can be said by analyzing the formation of forces at the Syrian border," Bayraktar explained.
"If you recall, the 'Euphrates Shield' operation was launched around this time last year, on August 24. Given that the area is incredibly hot in the summer months, if such an operation is being planned then it would take several weeks to implement, taking into account the climatic conditions."
This could help the Syrian army to regroup its forces from areas such as Idlib and make further gains against Daesh in the area around Deir ez-Zor, where the army recently drove out Daesh from Al-Sukhnah.
"I believe that contacts between the leadership of Turkey and Syria are being mediated by Russia, which maintains close cooperation with both Turkey and Damascus. Consequently, here Russia is the main player coordinating this issue. In particular, we see that the Syrian army and forces supported by Russia have now taken a very serious step towards moving towards Deir ez-Zor."
"De-escalation zones are needed in order for the Syrian army to strengthen its position here. In this sense, although Turkey does not completely dominate the Idlib region, it still has a strong enough position and the ability to influence the situation in this area."
"It is possible that Russia and the Syrian government forces, in exchange for the possibility to strengthen their positions in the strategically important region of Idlib, which is located very close to the Khmeimim air base, will agree to give the green light to Turkey to carry out the operation in Afrin, which Ankara regards as the stronghold of the Kurdish threat," Bayraktar said.