Turkish President Recep Tayyip Erdogan on Monday urged his Russian counterpart Vladimir Putin to extend the authorization for cross-border deliveries of humanitarian aid into Syria.

His appeal came as diplomats at the United Nations scrambled to find a solution that could overcome a Russian veto to a system that has kept aid flowing into the war-ravaged country since 2014.

Aid agencies warn that if Russia vetoes the resolution that would maintain two border crossing points from Turkey to deliver humanitarian aid, food would be depleted in Idlib and surrounding areas by September 2022, putting the lives of some 4. 1 million people, at risk.

“Erdogan emphasized that he attaches importance to the extension of the cross-border mechanism in Syria,” his office said in a statement issued after telephone talks following the expiry on Sunday of the mechanism.

The Kremlin made no mention of the Syria crossing in its readout of the call.

But it said the two leaders discussed preparations for a summit to be held “in the near future”.

Mr. Erdogan has been offering to meet Mr. Putin for months in an effort to help resolve global tensions that have intensified since Russia's invasion of Ukraine.

The Turkish-Syria border at the Bab Al Hawa crossing is the only way UN assistance can reach civilians without navigating areas controlled by Syrian government forces.

Russia used its veto power on the UN Security Council to strike down western proposals to keep the border crossing open for another year.

Western powers are resisting a Russian counter-offer to keep the crossing open for only six more months.

The UN Security Council has previously extended the cross-border mechanism after it has expired and several sources said a vote was still possible this week.

The Kremlin made no mention of the UN discussions and instead stressed the importance of the so-called “Astana process” for peace in Syria which besides Russia and Turkey also involves Iran.

Mr. Erdogan has tried to leverage his good working relations with both Mr. Putin and western-backed leaders in Kyiv to calm tensions.

His office said Mr. Erdogan also urged Mr. Putin to “take action” on a UN proposal for resuming stalled Ukrainian grain exports across the Black Sea.

The UN has submitted a plan that would see safe corridors set up around known mines, but it has gained only limited support in both Moscow and Kyiv.

Ukraine has accused Russia of stealing its grain and contributing to a global food shortage caused by grain exports blocked in its ports.

But Russia claims to have “nationalized” Ukrainian state assets and to be buying crops from local farmers.

The Kremlin signaled no clear progress on grain.

Mr. Putin and Mr. Erdogan “exchanged views on the situation around Ukraine, including in the context of efforts to ensure the security of Black Sea marine traffic and the export of grain to world markets,” the Kremlin said.

The call comes at a time of record food prices globally, with conflict in Ukraine, the world's largest grain supplier, fuelling fears about food security.