Turkish state media reported Wednesday that Ankara and Moscow have agreed to a proposal for a ceasefire covering all of Syria, but the Kremlin would not confirm the report.
Turkey's state-run Anadolu news agency said that proposal is now expected to be submitted to the warring parties in the Syrian conflict.
It claimed that the ceasefire could come into force as soon as midnight (2200 GMT) Wednesday, but terrorist organizations would be excluded.
Kremlin spokesman Dmitry Peskov said he could not confirm the report, but added that Russia and Turkey are constantly discussing ways to help resolve the Syrian conflict.
When asked whether the two sides had reached an agreement, Peskov said: "I cannot answer this question. I do not have enough information," according to the Interfax news agency.
A source in a Syrian opposition rebel group, who declined to be named, told dpa that "the details of the ceasefire were not presented officially yet" and that "there is no agreement so far."
Samir Nashar, a Syrian opposition figure, said that there are "tremendous efforts being exerted by the Turkish government to implement such a ceasefire with the help of an Arab country" before a proposed meeting to take place in the Kazakh capital Astana.
Russia has repeatedly demanded that the so-called moderate opposition in Syria split from organizations designated as "terrorists" by the United Nations, such as those linked to al-Qaeda.
Russia and Turkey are planning to host talks in January in Astana between the representatives of the Syrian opposition and the government.
Russia supports the regime of President Bashar al-Assad, while Turkey supports the opposition.
The foreign ministers of Turkey, Russia and Iran met last week in Moscow where they agreed to act as guarantor powers for a peace accord between the Syrian government and the opposition.
Months of bilateral tension after Turkey shot down a Russian warplane in November 2015 have eased significantly in recent months.
Turkish troops have for days engaged in fierce fighting with Daesh fighters in the battle to liberate the northern Syrian town of al-Bab.
On Tuesday evening, Turkish President Recep Tayyip Erdogan accused the US-led coalition of not doing enough to fight Daesh, even going so far as to accuse the coalition of supporting "terrorist" groups.