United Nations Secretary-General Antonio Guterres on Monday called for the Security Council to extend its authorization of cross-border aid from Turkey into northwest Syria by a year, a policy that veto-holding Russia has criticized. "We cannot give up on the people of Syria," he said.

The U.N. resolution allowing aid deliveries across the Syrian-Turkish border at Bab al-Hawa has been in effect since 2014 but is set to expire on July 10.

Nearly 10,000 trucks loaded with humanitarian aid passed through Bab al-Hawa last year bound for the opposition-held Idlib region. It is the only crossing through which aid can be brought into Idlib without navigating areas controlled by Damascus.

"I strongly appeal to the members of the Council to maintain consensus on allowing cross-border operations by renewing resolution 2585 for an additional 12 months," Guterres said at the Security Council's monthly meeting on Syria.

"It is a moral imperative to address the suffering and vulnerability of 4.1 million people in the area who need aid and protection," said Guterres.

"When it comes to delivering life-saving aid to people in need across Syria, all channels should be made, and kept, available."

Russia, an ally of Damascus, could veto a proposal to extend the cross-border aid mechanism, having already forced a reduction in the number of allowed border crossings on the grounds that it violates Syria's sovereignty. It says more aid should be delivered from inside the country, raising opposition fears that food and other aid would fall under the regime's control.

Guterres also reiterated his call for more support from donors for the people of Syria, saying "more is needed."

Guterres said the humanitarian situation in Syria remains dire for millions of men, women and children across the country, adding that needs are at their highest since the start of the war in March 2011.

"Our current humanitarian appeal requires $4.4 billion to assist people inside Syria and another $5.6 billion in supporting refugees in the region," he said.

"We have made great strides in scaling up the response, but more is needed. The generous pledges made at the Brussels VI donor conference need to be paid," he said. "I appeal to donors to follow through and increase their support."

According to the U.N. chief, 14.6 million people need humanitarian assistance and 20 million are food insecure while 90% of the population lives below the poverty line.

In northwestern Syria, Guterres said 2.8 million people, mostly women and children, are displaced and many live in camps or makeshift settlements.

"The massive humanitarian response the United Nations and its partners is conducting in Syria has staved off the worst, but more is required," he said.

"That is why I have consistently stated the importance of maintaining and expanding access, including through cross-line and cross-border operations," he added.

Guterres said that in the past year, the United Nations had carried out five such deliveries into the opposition-controlled northwest, but it was not "at the scale needed to replace the massive cross-border response."

Guterres said 80% of those in need in northwest Syria are women and children. Some 800 trucks a month deliver aid from Turkey under the U.N. operation, which Guterres asked to be extended for another year.

Turkey's U.N. Ambassador Feridun Sinirlioğlu asked: "Can anyone who respects human life and who respects the fundamentals of the U.N. Charter afford to disrupt such a vital system?"

Norway's deputy ambassador, Trine Heimerback, said ahead of the Council meeting that in addition to humanitarian aid, the resolution's renewal "will also facilitate further early recovery projects."

Her statement could be read as a hint that Western nations will assist in the early stages of Syrian reconstruction projects in exchange for Moscow allowing the cross-border aid resolution to pass.

Russia has long called for the West to participate in Syria's reconstruction, but some members of the Security Council, most vocally France, have refused until political reforms have been enacted.

"In the absence of a political solution, there is absolutely no reason to normalize relations with the Syrian regime and move towards reconstruction," reiterated the French deputy ambassador, Nathalie Broadhurst, on Monday.

The United States, for its part, also hinted at possible increased involvement in Syrian reconstruction projects.

The U.S. ambassador Linda Thomas-Greenfield, who recently visited the Syrian-Turkish border, said that she "reaffirmed U.S. support for early recovery efforts, which we know continue to be an important component of sustainable response efforts."

She told the council it had to make a "life or death decision" and that more aid, not less, is needed.

"Cross-line aid alone cannot come close to meeting the dire needs on the ground. It can reach thousands, but not millions. Much more help is needed," she said.

Russia's Deputy U.N. Ambassador Dmitry Polyanskiy described as "pitiful" the U.N. efforts to deliver aid to the northwest of Syria from within the country.

He said that Moscow is "convinced" that humanitarian aid can reach "all regions of Syria" via Damascus and blamed international sanctions for Syria's worsening humanitarian crisis.

China's U.N. Ambassador Zhang Jun said the cross-border aid operation was an "extraordinary arrangement" and that a timeline needed to be agreed to end it and transition to deliveries from within the country.

Dozens of aid groups and six senior U.N. officials called in separate statements last week for a year-long renewal of the cross-border aid authorization, which was last extended in January for six months.

In 2014 the Security Council authorized humanitarian aid deliveries into opposition-held areas of Syria from Iraq, Jordan and two points in Turkey. But veto powers Russia and China have whittled that down to just one Turkish border point.

Eleven years into Syria's civil war, 3 million people live under the rule of extremist or opposition groups 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.