America’s ambassador to the United Nations blasted Russia for delaying a vote on a ceasefire in Syria for the besieged area of eastern Ghouta, saying “the Syrian people can’t wait”.

“Unbelievable that Russia is stalling a vote on a ceasefire allowing humanitarian access in Syria,” Nikki Haley said on Twitter.

“How many more people will die before the The Security Council agrees to take up this vote? Let’s do this tonight.”

Hundreds of civilians are estimated to have died in a bombardment of eastern Ghouta, leading the US and others to urge a temporary ceasefire allowing humanitarian aid.

Debate around a ceasefire resolution extended into a second day after Russia objected to an earlier version that would have imposed a 30-day halt in hostilities, with UN ambassador Vassily Nebenzia calling the proposal “unrealistic” and accusing other council members of being misled by a “massive psychosis”.

Russia has been a key backer of Syrian leader Bashar al-Assad’s regime, lending military support to government forces in the bloody civil war.

As a permanent member of the UN Security Council, Russia wields veto power and has repeatedly blocked resolutions on Syria. In November it vetoed its 10th Syria-related UN resolution, a US-drafted call to investigate who was culpable for chemical weapons attacks.

Eastern Ghouta bombings: Syrian war in pictures Show all 14 1 /14 Eastern Ghouta bombings: Syrian war in pictures Eastern Ghouta bombings: Syrian war in pictures A Syrian woman and children run for cover amid the rubble of buildings. AFP/Getty Eastern Ghouta bombings: Syrian war in pictures Smoke rises from buildings following the attack on the village of Mesraba in the rebel-held besieged Eastern Ghouta region on the outskirts of the capital Damascu. AFP/Getty Eastern Ghouta bombings: Syrian war in pictures Injured children receive medical treatment. EPA Eastern Ghouta bombings: Syrian war in pictures A Syrian man carries a child injured. AFP/Getty Eastern Ghouta bombings: Syrian war in pictures An injured child receives treatment following bombings on several areas of eastern Ghouta. EPA Eastern Ghouta bombings: Syrian war in pictures A child reacts inside a hospital after relatives were injured in the bombing. EPA Eastern Ghouta bombings: Syrian war in pictures Syrian children cry at a make-shift hospital in Douma following air strikes on the Syrian village of Mesraba. AFP/Getty Eastern Ghouta bombings: Syrian war in pictures Syrian Civil Defense group extinguishing a store during airstrikes and shelling by Syrian government forces. AP Eastern Ghouta bombings: Syrian war in pictures A wounded 12-year-old Syrian boy, cries as he receives treatment at a make-shift hospital. AFP/Getty Eastern Ghouta bombings: Syrian war in pictures Syrians carry a wounded man. AFP/Getty Eastern Ghouta bombings: Syrian war in pictures An injured man covered with blood at a medical point. Reuters Eastern Ghouta bombings: Syrian war in pictures People sit a medical point in the besieged town of Douma, Eastern Ghouta. Reuters Eastern Ghouta bombings: Syrian war in pictures Syrian Civil Defense running to help survivors. AP Eastern Ghouta bombings: Syrian war in pictures Injured children receive medical treatment. EPA

The US this week accused Assad of a systematic campaign to “bomb and starve” residents of eastern Ghouta, a suburb of the regime-controlled capital of Damascus, with US ambassador for economic and social affairs, Kelley Currie, telling the UN Security Council attacks “have been relentless”.

“The regime wants to keep bombing and gassing these 400,000 people, and the Assad regime is counting on Russia to make sure the Security Council is unable to stop their suffering,” Ms Currie said.

Scenes of devastation in Syria after deadly shelling and airstrikes and eastern Ghouta

The UN’s Syria envoy, Staffan de Mistura, pleaded with members earlier this week to take action and prevent a “massacre”.