"On the instructions of the Russian president, with the goal of avoiding civilian casualties in Eastern Ghouta, from February 27 -- tomorrow -- from 9.00 to 14.00 there will be a humanitarian pause," minister Sergei Shoigu said at a ministry meeting, according to a statement sent to AFP.

He said there should be similar pauses in the southern Al-Tanf border region and Rukban, near the Jordanian border, "so that civilians can return to their homes unhindered and begin to rebuild their civilian lives".

Russia has denied air strikes on the enclave have killed civilians and insisted groups attacked by regime and allied forces are associated with terrorists.

More than 520 civilians are thought to have died in a week of heavy bombardment in Eastern Ghouta, just outside Damascus, by Syria's regime.

The US, rights groups and Syrian media have said Russian planes carried out the strikes, including on hospitals.

The UN Security Council on Saturday unanimously demanded a 30-day truce in Syria.

Russia is a key ally of Assad, and fought a campaign for over two years in Syria in his support, helping to turn around the multi-front war.