United Nations Syria envoy Staffan de Mistura "deeply regrets" the US suspension on Monday of talks with Russia on how to end the violence in Syria, but said the world body would "continue to push energetically for a political solution" to end the war.
“The UN will never abandon the Syrian people to a destiny of endless violent conflict,” Mr de Mistura’s office said in a statement.
Earlier a draft text had emerged suggesting The United Nations Security Council would urge Russia and the US to ensure an immediate truce inAleppo and to "put an end to all military flights over the city".
The draft text also asked UN chief Ban Ki-moon to propose options for a UN-supervised monitoring of a truce and threatened to “take further measures” in the event of non-compliance by “any party to the Syrian domestic conflict”.
It was not immediately clear how Russia and China would respond to the draft, diplomats said. Both countries have previously protected the Syrian government from council action by blocking several resolutions, including a bid to refer the situation in Syria to the International Criminal Court.
French foreign minister Jean-Marc Ayrault has said that any state that opposes the resolution would be deemed complicit in war crimes.
Syrian president Bashar al-Assad's forces, backed by support from Russia and Iran, have been battling for control of eastern Aleppo. Capturing the rebel-held half of Syria's largest city, where more than 250,000 civilians are trapped, would be the biggest victory of the five-year civil war for Mr Assad's forces.
East Aleppo came under siege in early July after its main supply route, the Castello Road, fell under government control.
International attempts to establish ceasefires to allow in UN humanitarian aid have failed, although other aid groups have brought in limited supplies.
The relentless Russian and Syrian air campaign has badly damaged hospitals and water supplies.