The reported departure of the Russians is another blow to Khalifa Haftar's Libya National Army (LNA).
Haftar, in an audio message addressed to his forces, urged them to battle the "colonial" intervention by Turkey until its defeat, in a reference to one-time Ottoman control of Libya.
Russia and Turkey made the agreement on Thursday evening after six hours of talks in Moscow.
Russia’s alliance with Turkey underpins new regional strategy in Middle East.
The Syrian regime hopes Russia has already brokered a deal with Ankara to allow it to crush HTS and divide Idlib.
Idlib was a “de-escalation” zone over the last two years but it was also a zone of contention, especially along the governorate’s borders.
The problem is that the US has no clear plan now for Syria, while its adversaries appear to have one.
Iran is a key ally of the Syrian government in the seven-year civil war and it says it has no intention of withdrawing unless Syria requested it do so.
The US and Russia, two world super-powers, and Turkey and Iran, the two regional Islamic powers, are locked into a deadly confrontation with no political issue in sight.