The UN on Tuesday (January 7th) urged global powers to renew a system for cross-border aid delivery to Syria that is due to expire this week, saying there was no alternative.
"There is no plan B. There is this operation, which helps hundreds of thousand of people and has done so for a very long time," said Jens Laerke, spokesman for the Office for the Co-ordination of Humanitarian Affairs (OCHA).
"It is the only viable, sustainable method that we have for reaching these people in need so it is critical that we get renewal of the provisions," he told reporters in Geneva.
Under the current system set up by the UN Security Council in 2014, humanitarian aid is allowed into Syria through four border crossings from Iraq, Jordan and Turkey.
Laerke said around 30,000 UN aid trucks had gone into Syria through the crossings since the operation began.
The arrangement is set to expire on Friday.
Four million supported by aid
When the UN Security Council took up the matter on December 20th, Russia and China vetoed a resolution that would have allowed continued aid deliveries for a year.
Russia, a key supporter of the Syrian government, has said it would support only a six-month extension, involving only two passage points on the Turkish-Syrian border.
Rounds of talks since then have failed to end the deadlock.
Laerke said some four million people in northern Syria were supported by UN cross-border aid, including 2.7 million in north-west Syria who relied solely on it.
The aid is particularly important for Idlib, an embattled opposition stronghold that has come under increasing bombardment from Syrian and Russian forces in recent weeks.
"The millions of people in Idlib, they are trapped," Laerke said, explaining that UN cross-border assistance could save lives by helping people on the ground.
The UN said at least 300,000 people have been internally displaced by the fighting in the Idlib region since mid-December, bringing the total number of displacements in the region to 700,000 over the last eight months.