Russia on Friday vetoed a UN Security Council resolution that would have extended the opening of a cross-border aid corridor to Syria by a year.
The authorisation for aid deliveries across the Syrian-Turkish border at Bab Al Hawa, which has been in effect since 2014 and does not require backing from Damascus, is set to expire on Sunday.
Russia vetoed a resolution drafted by Ireland and Norway that would have extended aid deliveries to some four million people in opposition-controlled north-west Syria from Turkey.
"This is a life and death issue. And tragically, people will die because of this vote and the country who shamelessly deployed the veto," US Ambassador to the UN, Linda Thomas-Greenfield, told the council.
"Tragically people will die because of this vote."
The resolution received 13 votes in favour, while China abstained.
Russia's deputy ambassador to the world body, Dmitry Polyanskiy, accused the west of "stubbornness" and said the resolution "ignored the sovereignty of Damascus."
Western nations had deemed the text unacceptable, as there is no guarantee of an extension at the start of the new year.
A resolution needs nine votes in favour and no vetoes by any of the council's permanent members — Russia, China, the US, Britain and France — to be adopted.
The 15-member council then voted on a proposal by Russia, a Syrian ally, to approve the UN operation for six months and also push for broad international reconstruction efforts in Syria. It failed with only Russia and China voting in favour, while the US, Britain and France voted against it and the remaining 10 council members abstained.
The UAE's ambassador to the UN, Lana Nusseibeh, said the failure to pass a resolution was a matter of deep regret.
“We had hoped that this council would be able to send a positive message today to the Syrian people, particularly at Eid Al Adha, a sacred occasion that should remind us all of the importance of giving and of compromise,” Ms Nusseibeh said.
Nearly 10,000 trucks loaded with humanitarian aid passed through Bab Al Hawa last year, bound for Idlib.
Moscow, an ally of Damascus, has curtailed a number of western-backed measures in recent years, using its veto 17 times in relation to Syria since the war's outbreak in 2011.
Russia views the authorisation as a violation of Syria's sovereignty, and believes the delivery of aid to the northwest region should only be carried out from Damascus across the front line.
- With agencies