Ukrainian President Volodymyr Zelenskyy has called for the removal of naval obstructions blocking food exports from his country.

"More than 100 ships transporting food are queued up near the Bosporus. Why? Because they need to be inspected, and Russian representatives are blocking this inspection. The ships have been detained for weeks," Zelenskyy said on Saturday in a video message to an international conference of agriculture ministers in Berlin. He also predicted higher food prices for Europe as a consequence.

For Asia, this also means a growing risk of social instability, and for countries in Africa like Ethiopia or Sudan, empty dining tables for thousands of families, Zelenskyy added, with a pledge to keep supplying the world with food.

Although Russia continued to fire missiles at Ukraine's infrastructure, including ports and transport, and wage brutal battles in regions crucial to agriculture, "Ukrainian farmers continue to cultivate the fields," he said.

Meanwhile, Russia on Saturday denied blockading Ukrainian grain ships and blamed Kyiv for creating an "artificial traffic jam."

"Currently, 64 ships are anchored at Ukrainian ports and inspection zones. The order for their inspection is determined by the Ukrainian side, and Russian representatives have no influence on this at all," said the Foreign Ministry in Moscow in a statement.

The Russian navy blockaded Ukraine's Black Sea ports immediately after the start of the war last February. Mediated by Türkiye and the United Nations, an end to the blockade was agreed upon last summer to defuse the global food crisis. However, Russian warships still reserve the right to inspect ships' cargo.

Last week, the United Nations also called out inefficiencies in the operation of the deal allowing Ukraine Black Sea grain exports but did not lay blame for a backlog of more than 100 ships in Turkish waters awaiting travel approval and inspections.

"The United Nations urges all parties to work to remove obstacles for the reduction of the backlog and improve operational efficiencies," it said in a statement.

U.S. Ambassador to the United Nations Linda Thomas-Greenfield earlier accused Russia of a "deliberate slowdown of inspections," saying that 5 million tons of food a month should be moving under the agreement.

Since November, three inspection teams have been deployed daily and have concluded 5.3 inspections a day so far this month, said the United Nations, adding, "In the last two weeks, the average waiting time for vessels between application and inspection has been 21 days."

It said some 3.7 million metric tons in Ukrainian exports moved under the deal in December, up from 2.6 million in November, while during the past two weeks nearly 1.2 million metric tons of exports shipped.

The package deal also includes facilitating Russian food and fertilizer exports, including ammonia, and the United Nations has been trying to negotiate a restart of Russian ammonia shipments via a pipeline to a Ukrainian Black Sea port.

"The parties negotiating on how to get ammonia to the market through the Togliatti/Yuzhny pipeline are still in discussions and are yet to reach an agreement," said the United Nations.