Geneva, 7 March 2023 (dpa/MIA) - UN Secretary General António Guterres is on his way to Kiev with the aim renewing a UN-brokered wartime grain export deal between Russia and Ukraine.

The Black Sea Grain Initiative - which was first agreed to last July after tough negotiations and then extended in November - is due to expire on March 19 if an agreement cannot be reached.

The deal frees millions of tons of grain and other foods that would otherwise be stuck in Ukraine due to Russia's invasion and blockade. It allows for shipments via three Black Sea ports, with Turkey playing a coordinating role.

The two countries supplied almost a quarter of the world's grain exports before the war. The scheme is seen as vital to preventing humanitarian crises in developing countries and to keeping global food prices in check.

This will be the third visit by the UN chief to the Ukrainian capital since the start of the war. He was expected to meet President Volodymyr Zelensky, among others, on Wednesday for talks on extending the deal.

Guterres first arrived in Poland on Tuesday.