The prospects for future aid deliveries to Syria looked bleak on Wednesday, with Russia and the US trading barbs over their actions in the war-torn Middle Eastern country. The clock is ticking on a UN Security Council mandate allowing aid convoys to cross into rebel-held north-western Syria from Turkey, supplying millions of civilians there. Unless renewed, it will expire in July. Russia says cross-border deliveries are no longer needed while the US and others want the checkpoint to stay open. Last year, Moscow and Washington clinched a deal to keep aid flowing thanks in part to a meeting between presidents Joe Biden and Vladimir Putin. But Russia’s invasion of Ukraine in February has tanked relations between Moscow and the West, making another eleventh-hour deal to keep Syria’s last-remaining aid crossing open appear remote. US ambassador Linda Thomas-Greenfield on Wednesday called the 2021 renewal “an important life-saving decision” that showed the “best of what we can do when we work together”. The top UN body should “renew the mandate again” and reopen shuttered checkpoints to ease rising humanitarian needs in Syria, she told the UN Security Council. She also said she would soon visit Bab Al Hawa checkpoint to see aid deliveries with her “own eyes”. But Russia, an ally of Syrian President Bashar Al Assad, wants the checkpoint shuttered, and, like the four other permanent council members — the US, Britain, China and France — it can veto major decisions of the 15-nation chamber. Russia says Al Nusra, Hayat Tahrir Al Sham and other armed groups fighting Mr Al Assad’s government from Syria's rebel-held north-west intercept aid convoys once they cross the Turkish frontier. Russia’s UN envoy Vasily Nebenzya said US and European Union sanctions on Damascus were to blame for Syria’s widespread humanitarian crisis — not the lack of cross-border convoys. “Establishing fully fledged peace and stability in that country is hindered by the illegal occupation by the US of a significant part” of Syria, Mr Nebenzya said in New York. He slammed “inhumane living conditions” and “havoc” in areas under effective US control, where authorities “plundered natural and agricultural resources”. This “is the recipe for how to combat the global energy and food crisis, according to the American way”, he said. China and Russia in early July vetoed a UN resolution that would have allowed two border crossing points from Turkey to remain open to deliver aid to Idlib. Days later, the council authorised the delivery of aid through only one crossing, Bab Al Hawa, for one year. UN aid chiefs say the 800 lorries that transit through Bab Al Hawa each month are needed to help about 2.4 million people in north-west Syria. David Miliband, president of the International Rescue Committee, said ordinary Syrians could be the next victims of a “divided council” and urged members to “break the deadlock”. The upcoming council vote “needs to be based on facts and law alone to ensure humanitarian aid reaches those in need by the most direct and effective routes”, Mr Miliband said.