Turkey and Russia form a working group in a bid to bring calm to the recent escalation in Syria's Idlib within the context of Astana and Sochi Agreements.
Turkey said on Friday that Syrian regime forces are violating a ceasefire agreement reached with Russia over Syria's Idlib province.
In recent weeks, that effort has been strained by the surge in violence in Idlib and Hama provinces, the last strongholds held by rebels.
Russia is backing the Syrian regime while Turkey has backed some rebels in Syria's eight-year-old civil war, but they have worked together to try to contain fighting in the country's northwest.
"The regime is not keeping its promises of a ceasefire despite the agreement and is violating the ceasefire," Defence Minister Hulusi Akar said in a statement on the ministry's website, adding that an escalation in violence could lead to a humanitarian tragedy.
"The Sochi agreement requires a ceasefire and that is what we want from the Russians. Meetings in Ankara are continuing right now," he said.
The ministry earlier said a joint working group between Ankara and Moscow had met in the Turkish capital on Thursday and Friday to discuss Idlib, the Sochi agreement and the Astana process - multi-sided efforts to try to provide stability in Syria.
The Assad regime has ignored the agreements and constantly strikes Idlib’s de-escalation zone.
Turkey and Russia agreed last September to turn Idlib into a de-escalation zone where acts of aggression would be expressly prohibited.
Moscow is piling pressure on Ankara to start an operation against the opposition-held areas after Turkey could not push rebels to agree to Russian patrols and get all militants out of a buffer zone that underpinned the Turkish-Russian deal.
Syria has been locked in a vicious civil war since early 2011, when the Assad regime cracked down on pro-democracy protests.
At least half a million people have been killed so far during the war and over 12 million displaced.
There's now a warning of the worst humanitarian crisis this century.