There was no immediate Turkish comment on the reports. There are no known plans by the Kurdish forces to take on al-Qaida-linked militants in Idlib.
Sejari said the operation aims to deploy Turkish-backed opposition fighters in the province now dominated by al-Qaida-linked militants. He said the plan is to also foil "foreign projects" that aim to occupy the north of Syria under the pretext of fighting terrorism, in an apparent reference to the USA -backed Kurdish forces.
Sofge said some 2,000 IS fighters were still in the area.
"As for the Russians, they will not have a role in the areas of our control at all".
The operation is linked to a deal agreed earlier this year by rebel backer Turkey and regime allies Russian Federation and Iran to implement four so-called "de-escalation zones" in Syria.
Turkish commando units and military vehicles have reportedly massed on the border but are yet to cross, in what will be Ankara's second major Syria operation after its Euphrates Shield incursion previous year.
He pointed out to the presence of serious action now taking place in Idlib to achieve security. Erdogan has announced the country is conducting a "serious" operation against extremist groups in Syria's northwestern Idlib province with Turkey-backed rebels.
"What is also possible is a joint operation between Turkish forces and the Free Syrian Army (FSA) against the terrorists".
HTS wants to continue fighting the government despite the establishment of "de-escalation zones".
Free Syrian Army fighters had reportedly entered Idlib Friday night, according to earlier media reports, but the Turkish president denied Ankara-backed forces had yet entered.
Turkish state-run Anadolu news agency said there was a major build up of Turkish commando units and military vehicles around the town of Reyhanli bordering Idlib close to the Cilvegozu border crossing.
Security in Idlib will be provided by Turkey with Russia, Erdogan said Saturday, without elaborating further.
Turkey's NTV, a private television station, reported an exchange of fire at the border area, quoting "military sources".
He said the defections could be read as "opportunistic in anticipation of a Turkish intervention".
"When you enter a boxing match, you don't count how many punches you will throw", Erdogan said.
A rebel commander participating in the operation, who spoke on condition of anonymity, told AFP in Beirut that "all the rebel groups" who took part in Euphrates Shield are participating in the latest operation. The zone would be monitored by Turkish soldiers.
Ahmed Abazeid, a Syrian researcher at the Turkey-based Toran Centre, said the Tahrir Al Sham coalition was always "essentially a sham".
President Erdogan refused to provide details on the extent of Turkish military deployment in Syria.
A December cease-fire in Syria brokered by the three countries led to the Astana talks, which are being held in parallel to UN-backed discussions in Geneva, to find a political solution to the six-year conflict.