Rival resolutions on Syria backed by the West and Russia were defeated in the UN Security Council on Saturday, offering no relief to the besieged city of Aleppo and leaving the key powers even more divided over a course of action in the war-ravaged country.

Russia vetoed a French-drafted resolution demanding an immediate halt to the bombing campaign against rebel-held districts in Aleppo. The rival Russian draft which made no mention of a bombing halt was rejected because it failed to get the minimum nine "yes" votes needed for approval by the 15-member council.

Russia's UN Ambassador Vitaly Churkin, the current rotating council president, said before the votes that members were engaging in "one of the strangest spectacles" in the Security Council, because they were meeting knowing that neither resolution would be adopted.

"This waste of time is inadmissible," he said.

The votes reflected the deep divisions in the UN's most powerful body which is charged with ensuring international peace and security but has totally failed to take action to end the more than five-year Syrian conflict which has killed over 300,000 people and displaced millions.

The French-backed resolution received 11 "yes" votes, two "no" votes from Russia and Venezuela, and abstentions from China and Angola. The Russian resolution received four "yes" votes, nine "no" votes, and two abstentions.

It was the fifth veto by Russia of a Western-backed resolution aimed at ending the Syrian conflict.

When Syria's UN Ambassador Bashar Ja'afari started speaking after the votes, a number of ambassadors walked out, including the representatives of Britain, France, Ukraine and the United States.

Russia's Churkin said the demand for a bombing halt in Aleppo was "not fleshed out" and would affect the government-controlled western part of the city as well as the rebel-held east.

He said the French resolution's adoption would have been the first where the Security Council decided on a course of action for a permanent council member without prior agreement - meaning that Russia would have been required to stop all flights and bombing of Aleppo.

Churkin noted that activity in Aleppo had gone down on Friday and "we hope this is a trend that will continue".

Until Friday afternoon, the French resolution was the only one before the council. But Russia unexpectedly introduced a rival resolution in a bid take some attention off its expected veto.

US Deputy Ambassador David Pressman said Russia and Syria would claim that any devastation in Aleppo that "they are raining down is directed at terrorists", not at civilian buildings.

Russia's Churkin said he wouldn't react to "provocative rhetoric".

He agreed that "more action is needed", but blamed the US for failing to separate the moderate opposition from the extremists as called for in the failed US-Russia cease-fire agreement.