Turkish President Recep Tayyip Erdogan's recent statement led to a dispute with the US concerning the safe zones in Syria.
Erdogan on Monday said Ankara would soon launch new military operations along its southern borders to create safe zones 30 km (20 miles) deep to combat what he characterized as terrorist threats from these regions.
Erdogan has said the National Security Council would make decisions on military operations at its Thursday meeting.
Recent reports stated that Turkish armed forces and the Turkey-backed Syrian National Army might be targeting Tal Rifaat, Ayn al-Arab (Kobani), Ain Issa, and Manbij.
Turkish sources said that the memorandum of understanding (MoU) signed with the US on October 17, 2019, has not been implemented. It addresses the withdrawal of the Kurdish People's Protection Units (YPG), the largest component of the Syrian Democratic Forces (SDF), to 30 km from the southern Turkish border.
The sources told Asharq Al-Awsat that the MoU was signed to stop the military operation "Peace Spring," which Turkey launched on October 9, 2019, in the SDF-controlled areas east of the Euphrates.
They explained that the withdrawal process was scheduled within five days, but it never happened.
Earlier, the United States warned of any new attack in northern Syria, saying it would undermine stability in the region and endanger its forces.
"We are deeply concerned about reports and discussions of potential increased military activity in northern Syria, and in particular, its impact on the civilian population there," State Department spokesperson Ned Price said on Tuesday.
"We recognize Turkey's legitimate security concerns on Turkey's southern border, but any new offensive would further undermine regional stability and put at risk US forces and the coalition's campaign against ISIS," he said.
Washington was expecting Ankara to live up to an October 2019 joint statement, including a halt in offensive operations in northeastern Syria, Price said.
"We condemn any escalation. We support the maintenance of the current ceasefire lines."
Meanwhile, the Syrian Foreign Ministry sent a letter to the UN Secretary-General and the Security Council describing Turkey's actions as illegitimate.
"They amount to what can be described as war crimes and crimes against humanity," it said in a statement carried by the state news agency.
Turkey objects to Finland and Sweden's bid to join the North Atlantic Treaty Organization (NATO) over their alleged support for the Kurdistan Workers' Party (PKK) and the YPG, two groups that Ankara classifies as terrorist organizations.
Observers considered that Erdogan's sudden announcement reflects his belief that the West will not oppose such operations because they need Turkey's support for the two European countries' bid to join NATO.
They pointed out that the Turkish army's movement against the YPG in Syria, Washington's closest ally in the war against ISIS, has always been possible despite the relative calm along the border.
Observers considered that Erdogan is seeking to seize the opportunity to achieve his long-standing goal of establishing a zone free of Kurdish militants along the Turkish border with Syria.
Possible targets of the Turkish operation
The pro-government Yeni Safak newspaper said preparations had been made for a new operation to expand "safe zones" already set up in northern Syria, with several goals identified.
Turkish control of the towns, which lie on or close to a central stretch of the 911-km-long border with Syria, could extend and deepen its military presence near the Mediterranean coast along nearly three-quarters of the frontier.
YPG spokesman Nuri Mahmoud told Reuters the group took Erdogan's threats very seriously: "The international coalition, America, and Russia should commit to the pledges they made to this region. Their presence in our areas must be meaningful, in the sense that it stops the repeated attacks on our people."
The Yeni Safak newspaper said the most critical target of the latest operation would be Tal Rifaat, which it said Kurdish fighters used as a base to launch attacks in the Afrin, Azaz, and Jarablus areas controlled by Turkey and Ankara-backed Syrian fighters.
Analyst on Syria at the International Crisis Group Dareen Khalifa said it was unclear whether Erdogan was talking about an operation in Tal Rifaat or further east, but she highlighted the town's role.
She said Russia had not been addressing his concerns on militant attacks on Turkish-controlled areas from Tal Rifaat and that Erdogan has been saying for years that Tal Rifaat needs to be captured.
According to a Reuters report, the predominantly Kurdish town of Kobani may be another potential target.
The YPG's defeat of ISIS militants there in 2015 helped turn the tide against the group.
"Kobani represents the value of a global victory in the war against terrorism," a YPG spokesman said.
Mahmoud asserted that "there's no doubt that our forces will do what is needed to defend" the area.
However, Khalifa played down the prospects of Turkey targeting Kobani.
"I don't think there's any interest in getting stuck in Kobani," she said, pointing to the significant demographic changes and reaction if the Kurdish population fled.
She said that while US forces were not in Manbij physically, it is a US zone of influence, so "I expect it also to trigger a US reaction."