A United Nations official visiting Syria's Idlib Tuesday urged for a 12-month extension of a cross-border aid mechanism to the war-torn country’s opposition-held north, which was hit by a deadly earthquake in February.

"There is no substitute in size and scope to the U.N. cross-border resolution if we want to meet the needs of the most vulnerable people in northwest Syria," said David Carden, the United Nations deputy regional humanitarian coordinator for the Syria crisis.

"It's a joint message that you're hearing from the U.N., the NGOs and the communities themselves in northwest Syria about the need for a 12-month renewal of the cross-border resolution," he told a press conference at a World Food Programme (WFP) warehouse in Sarmada.

The mechanism, which is renewed by a vote of the Security Council, allows vital U.N. assistance to reach people in rebel-held northwest Syria without navigating areas controlled by government forces.

It was last renewed in January and is set to expire on July 10.

Carden said a 12-month extension of the resolution would "ensure that aid will continue to flow during the desperate winter months. It will ensure that early recovery programs can be implemented."

The U.N. largely delivers the relief via neighboring Türkiye through the Bab al-Hawa crossing.

After a Feb. 6 earthquake devastated parts of Türkiye and Syria, Damascus agreed to open two more crossings from Türkiye – Bab al-Salama and Al-Rai – for three months, and in May extended that access for another three-month period.

"There are 4.1 million people in need in northwest Syria," Carden said, adding that "the needs are immense. They've got more severe since the earthquake."

"The United Nations and its partners have been reaching 2.7 million people with aid every month," he added, noting that "about 75 to 80 percent of the trucks that cross the border through Bab al-Hawa into Idlib contain food."

Syria's war has killed more than half a million people and displaced millions since erupting in 2011 with a brutal crackdown on anti-regime protests.

The number of U.N.-approved crossings shrunk from four in 2014 after years of pressure from regime allies China and Russia at the U.N. Security Council.

For years, Moscow has pressured international organizations to pass exclusively through regions under the control of Damascus to distribute aid throughout the country – going as far as vetoing cross-border extensions that exceeded six months.