Millions of people in northwestern Syria are "pressed up" against the border and remain in dire need of humanitarian aid to survive, heads of seven UN agencies said in a joint statement, Anadolu Agency reported.
The officials, including the UN Refugee Agency head and his World Food Program counterpart, said the UN needs cross-border and cross-line access to reach those most in need.
"We call for the renewal of Security Council authorization for cross-border operations from Turkey to northwest Syria," said the statement issued on Friday.
"A failure to do so would immediately stop UN delivery of food, COVID-19 vaccines, critical medical supplies, shelter, protection, clean water and sanitation, and other life-saving assistance to 3.4 million people, including 1 million children," it added.
The officials said that the UN continued its engagement with all concerned parties to allow cross-line convoys into the northwest.
"They are critical for the expansion of the overall response, but even if deployed regularly they could not replicate the size and scope of the cross-border operation. There is simply no alternative," they said.
The officials underlined that a large-scale UN cross-border response for an additional 12 months remains essential to avert a humanitarian catastrophe in northwest Syria.
Syria has been in a civil war since early 2011 when the regime cracked down on pro-democracy protests with unexpected ferocity.
Around half a million people have been killed, and more than 12 million had to flee their homes in the past decade.