First Ukraine grain ship leaves Odessa port

"Deployment of other ships are planned within the scope of the determined corridor and method" agreed on 22 July by Russia, Ukraine, Turkey and the UN, it said.

The export agreement aims to facilitate the safe transport of grain and other agricultural products from Ukrainian ports. Under the deal, a joint coordination centre, which launched operations last week in Istanbul, would monitor commercial vessels exporting Ukraine's grain to ensure compliance.

Ukrainian officials said there were 17 ships stuck in Ukraine's Black Sea ports, containing almost 600,000 tonnes of cargo.

Russia and Ukraine export nearly a third of global wheat and barley supplies.

Over 12 percent of the world's wheat, 15 percent of corn and 50 percent of sunflower oil come from Ukraine, most of which are normally shipped by sea.

But the country's export-capacity has significantly decreased since the war began in late February due to the long blockade of the Black Sea.

Ukraine warned on Sunday (31 July) that the country's harvest itself could be cut in half this year due to the war.

"Ukrainian harvest this year is under the threat to be twice less," Ukraine's president Volodymyr Zelensky said on Twitter.

He said that Ukraine's "main goal" was to prevent a global food crisis that is currently unfolding due to export disruptions in the Black Sea. "Still grains find a way to be delivered alternatively," he added.

Ukraine is expected to harvest up to 60 million tonnes of grain, according to UN estimates. 

Global food prices have been increasing since the pandemic.

But export disruptions in Ukraine and Russia have pushed prices even higher, raising fears over a looming hunger catastrophe in some African countries, Southern Asia, and the Middle East.

The World Bank warned this month that the conflict in Ukraine will push an additional 95 million people into extreme poverty, and 50 million into severe hunger.