Turkey's foreign minister says it has agreed with Russia a proposal for a ceasefire in Syria, where they back opposing sides in the civil war.
Mevlut Cavusoglu said a document outlining a political solution to the conflict was also "ready", and that both could be "implemented any time".
His comments came hours after Turkey's state news agency said a ceasefire might start at midnight (22:00 GMT).
A Kremlin spokesman said he could not comment on Anadolu's report.
Dmitry Peskov told reporters that Russian officials were "constantly in touch with our Turkish colleagues" to discuss details about possible peace talks in Kazakhstan next month.
There was also no immediate response from the Syrian government, while rebel officials could not confirm that anything had been agreed.
Russia - which has carried out an air campaign in support of President Bashar al-Assad - and Turkey - a major backer of the rebellion - announced last week that they were ready to help end the war.
Along with Iran, another staunch ally of President Assad, they agreed a set of principles for any peace deal.
Earlier this month, Moscow and Ankara negotiated a ceasefire in the northern city of Aleppo that led to tens of thousands of rebel fighters and civilians being evacuated from an enclave besieged by government forces.
On Wednesday morning, Turkey's official Anadolu news agency cited an unnamed Turkish source as saying the two countries had "agreed on a plan for the warring parties in Syria to declare a nationwide ceasefire".
The source said it would come into force in areas where government and rebel forces were fighting, and that "terrorist organisations" would be excluded, without giving further details.
Mr Cavusoglu was later asked about the report by a small group of journalists on the sidelines of an awards ceremony at the presidential palace in Ankara.
"There are two texts ready on a solution in Syria. One is about a political resolution and the other is about a ceasefire. They can be implemented any time," he was quoted as saying by the Reuters news agency.
The foreign minister also stressed that Syria's opposition would never agree to President Assad remaining in power as part of any political transition.
One Syrian rebel official told Reuters that there had been discussions about the proposed ceasefire with Turkish officials, but could not confirm whether anything had been agreed. Another said nothing had been presented officially.
The last round of UN-brokered talks aimed at finding a political solution to the conflict ended in April, after a nationwide cessation of hostilities negotiated by Russia and the US the previous month collapsed.
Another cessation of hostilities agreed in September was meant to see the US and Russia co-ordinate air strikes against two UN-designated terrorist organisations - so-called Islamic State and the rival jihadist group Jabhat Fateh al-Sham. But it also broke down within days.
In a separate development on Wednesday, Russia's foreign ministry said its embassy in Damascus had been shelled, but that there were no casualties.
Meanwhile, activists said at least 22 civilians, including 10 children, had been killed in an air strike on an IS-held village in the eastern province of Deir al-Zour.
The Syrian Observatory for Human Rights, a UK-based monitoring group, reported that unidentified warplanes had bombed the village of Hajna on Tuesday night.
IS-held territory in Syria is frequently targeted by the Syrian and Russian air forces, as well as a US-led multinational coalition battling the jihadist group.