Bloomberg reported Wednesday that Turkish forces had begun crossing into Syrian territory, citing a Turkish official speaking on condition of anonymity.
The official gave no further details on the alleged start of the operation.
However, a Sputnik Turkey correspondent challenged the claim, suggesting that Turkish troops and vehicles had not yet crossed the Syrian border.
Shortly after, Turkish officials cited by Reuters said that an operation in Syria had not begun, although troops and heavy equipment had removed a block at a section of the border wall between the two countries.
Earlier, Turkish Defence Minister Gen. Hulusi Akar said preparations for an operation in Syria, including troop and equipment transfers, were ongoing.
Also on Wednesday, Syrian Kurdish representatives announced a "general mobilisation" in northeastern Syria to prepare for a possible Turkish incursion, and urged the international community to prevent a possible "humanitarian catastrophe."
"We call upon our people, of all ethnic groups, to move toward areas close to the border with Turkey to carry out acts of resistance during this sensitive historical time," a statement, put out by a local Kurdish authority known as the Autonomous Administration of North and East Syria, read.
On Tuesday, Turkish presidential communications director Fahrettin Altun published a column in the Washington Post in which he suggested that Presidents Erdogan and Trump had agreed to "transfer the leadership of the counter-Daesh [ISIS] campaign" to Ankara, and wrote that Turkish forces, "together with the Free Syrian Army, will cross the Turkish-Syrian border shortly." Altun called Kurdish YPG fighters, which Ankara classifies as 'terrorists', to defect and join the Turkish-led effort, or face attack. Altun did not specify a concrete timeframe for the possible invasion.
Turkey has repeatedly voiced concerns regarding the Syrian Kurdish forces on its southern border, which have de facto control over northern Syria, and has repeatedly vowed to launch incursions into northern Syria to force the Kurdish fighters out. Among Turkey's allegations is the claim that the YPG cooperates with the PKK, a Turkish Kurdish militant movement waging a low intensity guerrilla campaign against Ankara.
In August, US and Turkish officials declared a commitment to establishing a safe zone in northern Syria, under which YPG forces would be required to remove its fighters and weaponry from the area. In October, the US began removing its troops from the area, with the White House indicating recently that it would not "support or be involved in" Turkey's planned operation.
Damascus has repeatedly condemned all unauthorised military operations on Syrian territory, whether planned or ongoing, and has called on all uninvited militaries to leave Syria immediately.
Russian Foreign Minister Sergei Lavrov has called for a dialogue between the Syrian government and Kurdish forces, including a commitment to resolve the "problems of ensuring security on the Turkish-Syrian border." Iranian President Hassan Rouhani, meanwhile, has called on a "correct path" to "be adopted" to remove Turkish concerns over its southern borders, including the removal of US troops in the region. Kurds, Rouhani said, "should support the Syrian Army." On Wednesday, Iranian media reported that Iran's military had begun an unannounced military drill near the border with Turkey.