Staffan De Mistura called on guarantor countries Turkey, Russia and Iran for an immediate meeting for re-establishing 'tension reduction zones', in a statement read out by UN spokeswoman Alessandra Vellucci during a briefing in Geneva.
De Mistura underlined that immediate, unhindered humanitarian access to Eastern Ghouta, as well as evacuation of the sick and injured had to follow the cease-fire.
On Thursday, Russia's permanent representative to the UN, Vassily Nebenzia said Russia would not support a UN Security Council proposal calling for a one-month humanitarian cease-fire in Eastern Ghouta unless some changes were made.
Nebenzia described the proposal as unrealistic.
Home to some 400,000 people, Eastern Ghouta has remained under a crippling siege for the last five years, bringing it to the verge of humanitarian catastrophe.
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