Putin and Erdogan set to discuss Ukraine grain exports during Iran meeting

Officials from Russia, Ukraine, Turkey and the United Nations will most likely meet this week to discuss resuming Ukraine's Black Sea grain exports, Ankara said on Monday, while a Turkish official said lingering "small problems" should be overcome.

Russia's invasion of Ukraine - two major global wheat suppliers - has sent prices for grains and other food products soaring. It has stalled Kyiv's exports, leaving dozens of ships stranded and some 20 million tonnes of grain stuck in silos at Odesa.

Last week Turkish Defence Minister Hulusi Akar said Russia, Ukraine, Turkey and the UN would sign a deal this week on the grain exports corridor after talks in Istanbul. But, UN chief Antonio Guterres warned there was still "a long way to go" before there would be peace talks to end the war.

"An agreement was reached on a plan, general principles for shipping grain and food products... A meeting on this within the week is probable," Akar said on Monday.

He said technical matters like forming a monitoring centre in Istanbul, identifying safe routes, and checkpoints at port exits and entries were on the agenda.

Separately, a senior Turkish official said there was a high probability the quartet would sign a deal this week.

"However there are a couple of small problems. Negotiations continue to overcome these," the official said, adding that any positive steps were affected by an attack or other major developments occurring in the war.

"But there is a general expectation that it will be signed this week. I am quite optimistic. It won't take long before a final agreement is reached," the person added.

At the weekend, Russia vowed to step up military operations in Ukraine as its rockets and missiles pounded cities.

A Kremlin aide told reporters on Monday that the presidents of Russia and Turkey would discuss the issue during a meeting in Tehran on Tuesday

The two leaders will meet in the Iranian capital with the conflict in Ukraine massively hampering shipments from one of the world's biggest exporters of wheat and other grain, sparking fears of global food shortages.

Erdogan and Putin alongside Iranian Supreme Leader Ayatollah Ali Khamenei are expected to discuss the future of Syria during their meeting in Tehran, as part of the Astana process.