Turkey and Russia have agreed a ceasefire plan for all of Syria that should come into force at midnight, Turkish state media said Wednesday, as Ankara and Moscow tighten cooperation to find an end to the civil war.

The plan aims to expand a ceasefire in the city of Aleppo, brokered by Turkey and Russia earlier this month to allow the evacuation of civilians, to the whole country, the state-run Anadolu news agency said.

But in a speech in Ankara after the report was published, President Recep Tayyip Erdogan made no reference to the plan, while Kremlin spokesman Dmitry Peskov said he could not answer on an issue "about which I don't have enough information".

A Syrian rebel source, who asked not to be named, told AFP in Beirut that details still had to be submitted to the rebel groups and said there was no agreement as yet.

Like previous ceasefire plans brokered by the United States and Russia, it excludes "terror" groups, the agency said.

If successful, the plan will form the basis of upcoming political negotiations between the Damascus regime and opposition overseen by Russia and Turkey in the Kazakh capital Astana, it added.

It was not immediately clear how and where the plan had been agreed but there have been talks in recent weeks between Turkey, Russia and Syrian opposition representatives in Ankara.

Heading to Astana? 

Qatar-based channel Al-Jazeera said a new meeting is planned on Thursday in Ankara, this time between military representatives of Syrian rebels and Russia.

Ankara and Moscow have been on opposing sides in the Syrian civil war, with Turkey seeking the ouster of President Bashar al-Assad, who is backed by Russia and Iran.

But the two countries have recently started to cooperate more closely on Syria, especially after a deal in the summer to normalise ties battered by Turkey's shooting down of a Russian warplane last year.

Ankara remained conspicuously quiet as Assad's forces, backed by Russia, took control last week of Aleppo in the biggest defeat so far for the rebels in the civil war.

No date has yet been set for the Astana talks and Russian foreign ministry spokesman Maria Zakharova said the meeting was still at the planning stage.

She emphasised that the talks were not intended to replace the peace process based in Geneva which has sought to find a solution for the Syrian conflict.

But the direct bilateral involvement of Turkey and Russia comes as Erdogan is increasingly expressing impatience at the role of the United States in Syria.

Previous ceasefire plans had been brokered by US Secretary of State John Kerry and Russian counterpart Sergei Lavrov. They met with only temporary success and failed to lead to a solution for the conflict.

It remains unclear how the latest ceasefire plan will apply to the Fateh al-Sham, formerly the Al-Qaeda affiliate Al-Nusra Front, which has worked more closely with the rebels since changing its name.

'Geneva empty'

Erdogan had on Tuesday launched one of his most bitter attacks yet on US and Western policy in Syria, which he said was marked by broken promises.

He accused the West of not just supporting Kurdish militia that Ankara regards as a "terror group" but even Islamic State (IS) jihadists.

Turkey has been enraged by the US policy of using the Kurdish Peoples' Protection Units (YPG) as a trusted ally on the ground against IS. To Ankara's pleasure, Russia has steered clear of overt cooperation with the YPG.

The Turkish strongman accused the West of failing to back Turkey's own incursion inside Syria in support of pro-Ankara fighters to oust IS from the border area, which has taken increasing casualties in recent weeks.

Backing the talks in Astana, Erdogan was dismissive of the Geneva process. "Unfortunately, Geneva came up empty. How many meetings were held? And no results were obtained," he said.

In continued bloodshed, air strikes carried out by unidentified aircraft killed at least 22 civilians, including 10 children, in a village held by IS in Deir Ezzor province, the Syrian Observatory for Human Rights said.

Syria's civil war, which began in 2011 as an uprising against Assad, has now lasted nearly six years and killed more than 310,000 people.