The resolution was last extended in January for six months.
“The magnitude of the crisis demands the reauthorization of cross-border assistance for a minimum of 12 months,” an open letter to the Security Council signed by aid groups including the International Rescue Committee, Norwegian Refugee Council, and Save the Children said.
“Anything less would signal to Syrians that the Council is willing to accept unnecessary suffering and loss of life,” the letter added.
Observers say Russia is using the threat of closure of the aid entry point as a bargaining chip in the face of punishing EU and US sanctions over Moscow’s invasion of Ukraine.
Russia has argued aid can instead transit via Damascus-controlled parts of the country across conflict lines.
But aid groups have been reluctant to shift their massive operations to go through areas held by the regime of President Bashar al-Assad, itself subject to sanctions.
Nearly 10,000 trucks loaded with humanitarian aid passed through the Bab al-Hawa crossing last year bound for the Idlib region, the last rebel bastion in Syria and home to around three million people.
Should aid cease, more parents will be “forced to choose between skipping meals or sending their children to work; more girls forced into early marriage to provide income for food; and more children forced out of school,” the letter said.
Eleven years into Syria’s civil war, three million people live under the rule of jihadists and allied rebels in the Idlib region.
Half of them have been uprooted from their homes in other parts of the country and rely heavily on international aid.