Russian President Vladimir Putin and Turkish President Recep Tayyip Erdogan

Turkish President Recep Tayyip Erdogan and his Russian counterpart Vladimir Putin held a phone call, during which they discussed several issues, such as bilateral ties, Kurdish forces in Northern Syria, and starting work on exporting other commodities and food products through the Black Sea grain corridor, according to Erdogan's office on Sunday.

A readout from the Turkish presidency stated that the two presidents discussed bilateral ties between the two countries, in addition to energy and combating terrorism.

It is "important to clear the (Kurdish fighters) from the border to a depth of at least 30 kilometres," Erdogan said, noting it was "a priority," the presidency's office stated.

Erdogan has been threatening to conduct a new military incursion into northern Syria to move out Kurdish forces which he blames for the November bomb blast that killed six people in Istanbul. The Turkish President also said his country is committed to destroying the Kurdistan Workers' Party (PKK) "until its last militant is neutralized" and raised the possibility of conducting a ground operation soon.

It is worth noting that on November 20, Turkey launched airstrikes that targeted military bases belonging to the PKK and its armed wing, the YPK, in both northern Syria and Iraq.

Turkish Defense Minister Hulusi Akar announced last month that Turkey had launched the "Operation Claw-Sword" offensive with airstrikes targeting Kurdish militants in Iraq and Syria.

The Turkish warplanes also targeted a site of the SDF in Khafiyyat Al-Salem silos, west of Ain Issa district, north of Raqqa.

The SDF accused Turkey of launching airstrikes on the city of Ayn al-Arab. The raids come days after Ankara accused the PKK of being behind the Istanbul attack.

Russia has been receiving indications from Ankara and Damascus about being open to making steps towards one another and about hopes for a Syrian-Turkish rapprochement, Russia's special presidential envoy for Syria, Alexander Lavrentyev, told reporters on November 23, following the 19th round of the Astana talks on Syria.

Moscow believes the Kurds were "given the go-ahead" to carry out a terrorist attack in Istanbul, he added, and has asked Turkey to refrain from a full-scale ground offensive in Syria because such actions could trigger an escalation of violence.

Since 2016, Turkey has engaged in three operations in northern Syria, which have resulted in the occupation of the region. The operations are Euphrates Shield (2016), Olive Branch (2018), and Peace Spring (2019).

A 2019 agreement between Russia and Turkey ended another offensive by setting up a 30-kilometre (19-mile) "safe zone" to protect Turkey against cross-border attacks from Syrian territory.

It is no surprise that the US plays a role in all this

As an extension of Washington's long-standing support for the PKK in northern Syria, a report by Turkish daily Yeni Safak wrote that the US continues to support the PKK by resuming joint patrols in northern Syria, in addition to arming them in areas where the Turkish forces are going to conduct a ground military operation.

The United States has been arming terror groups in northeastern Syria, making grounds for oil and gas theft. In August, SANA reported that US armed forces looted a convoy of 65 tankers filled with oil from the region of Al-Jazeera, then headed toward their military bases in Iraq, smuggling their looted cargo via the illegal Al-Mahmudiyah border crossing.

Yeni Safak writes that the US' support for the PKK sends a message: "We are with you!"