At least 428 people, including 98 children, have been killed in the aerial offensive on the besieged rebel suburb of Damascus in one of the worst episodes of violence in the seven-year-long war.
A sixth day of air strikes, including illegal barrel bombs, shelling and rocket fire, continued unabated in the area on Friday. More than 22 medical facilities have been damaged, leaving thousands of injured people unable to access adequate help.
The UN is due to vote on a resolution at 1600 GMT on Friday which would order a temporary cessation of hostilities and immediate access for aid convoys to millions across the country.
Ahead of the vote, the European Union issued a statement from all 28 members insisting on the importance of a ceasefire.
“The European Union is running out of words to describe the horror being experienced by the people of eastern Ghouta,” the bloc said.
“Unhindered humanitarian access and the protection of civilians is a moral duty and a matter of urgency... the fighting must stop now.”
On Thursday Foreign Minister Sergei Lavrov said that Russia would consider a resolution which did not cover Isis, the Nusra Front and other groups who are shelling residential quarters of Damascus.
However, it is al Qaeda linked groups in east Ghouta - believed to make up a small proportion of the rebel fighters there - which Mr Assad’s forces say they are currently targeting, raising the possibility any agreed ceasefire would not cover Ghouta.
The area is supposedly already covered by a 2017 “de-escalation” agreement brokered by several world powers.
At the Security Council in New York on Thursday several Western countries accused Russia of “stalling for time” by asking for changes to the draft which would create “loopholes” to continue the current assault.
France’s representative said that a failure to act on the “tragedy” in Syria could spell the end of the United Nations itself.
“Everything must be done to avoid a humanitarian crisis that flouts every principle the organisation stands for,” Francois Delattre added.
Russian ambassador Vassily Nebenzia said that the international community was suffering from “mass psychosis” over the situation.
“Global media outlets acting in coordination, disseminating the same rumours in recent days, in no way does anything to help improve understanding of this situation,” Mr Nebenzia told the council session.
East Ghouta’s rebels have responded to the Syrian and Russian operation with some of the worst rocket attacks on neighbouring areas of Damascus in years, killing 16 people.
Syrian state media reported that peace talks with the rebels over medical evacuations and aid deliveries in the last few days have failed.
Several previous UN-brokered ceasefire attempts in Syria have quickly fallen apart over the course of the seven-year-long war.
More than 500,000 people have been killed in the complex conflict, and half the pre-war population of 22 million displaced from their homes.
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