ANKARA/AMMAN (REUTERS) - Turkey's President Tayyip Erdogan said on Wednesday (Feb 19) a Turkish military operation to push back a Syrian government offensive against rebel strongholds in north-west Syria was now "a matter of time", after talks with Russia failed to halt the assault.
Turkish troops have already massed inside Syria ready to act and more were heading to the border area.
The Kremlin, which backs Syrian President Bashar al-Assad, said a confrontation between Turkish and Syrian forces would be a "worst-case scenario" and Russia would keep working to prevent the situation from worsening.
Syrian troops supported by Russian warplanes and special forces have been battling since December to eradicate the last rebel bastions in Idlib and Aleppo provinces in what could be one of the final chapters of the nine-year-old civil war.
Nearly one million civilians have fled from air strikes and artillery barrages towards the frontier, overwhelming relief agencies and alarming Turkey, which is struggling to cope with the 3.6 million Syrian refugees already camped inside its borders.
Speaking to lawmakers from his ruling AK Party on Wednesday, Mr Erdogan said Turkey was determined to make Idlib a secure zone even while talks with Moscow continued. Several rounds of diplomacy had failed to reach an agreement so far, he said.
"We are entering the last days for the regime to stop its hostility in Idlib. We are making our final warnings," said Mr Erdogan, whose country has the second-largest army in NATO.
"Turkey has made every preparation to carry out its own operational plans. I say that we can come at any point. In other words, the Idlib offensive is only a matter of time." The Turkish leader on Saturday appeared to move forward the end-of-February deadline for a Syrian withdrawal from Idlib that he had previously stated.
Mr Assad, whose family dynasty has ruled Syria for nearly half a century, has showed no sign of bowing to the demand, saying on Monday that his military gains presaged the eventual defeat of his foes. They include Turkish-backed rebels and militants.
An opposition military source told Reuters that 15,000 Turkish soldiers were now in north-west Syria after numerous convoys of reinforcements and weaponry had poured into the territory in recent days.
"You can't imagine the scale of Turkish reinforcements, half of Reyhanli is now full of Turkish commandoes ready to enter Syria," he said, referring to a Turkish border town. "They are readying their forces for zero hour, operations are expected to start any time."
Ankara and Moscow signed an agreement in 2018 to establish a de-escalation zone in Idlib allowing both sides to set up observation posts. Since the escalation in the conflict, both sides have accused each other of flouting the agreement.
In Moscow on Wednesday, Russian Foreign Minister Sergei Lavrov said Syrian forces were upholding previous agreements but also reacting to provocations.
Kremlin spokesman Peskov also said: "If we talk about an operation against legitimate Syrian authorities and armed forces, it is of course a worst-case scenario."
Russia has a naval base at Tartus and an airbase at Hmeimim.
Its war planes launched an air campaign in Syria in 2015, turning the tide of the war in Mr Assad's favour.
The recent air strikes in the north-west have hit hospitals and camps for displaced people, the United Nations has said.
Close to 900,000 people, most of them women and children, have fled their homes in dreadful winter conditions since December in the biggest displacement of the war.
In the past week the Syrian army has taken full control of dozens of towns in the Aleppo countryside and the M5 highway linking Damascus to Aleppo.