"(A) bulk carrier loaded with 40 tons of grain was supposed to leave the Ukraine port today," Ukraine Infrastructure Minister Oleksandr Kubrakov tweeted.
"These foodstuffs were intended for Ethiopians that are on the verge of famine. But due to the blockage of the 'grain corridor' by Russia the export is impossible," the minister said.
The Infrastructure Ministry said 218 vessels were "effectively blocked" by the Russian decision to withdraw from the grain shipping agreement.
The agreement had already allowed more than nine million tons of Ukrainian grain to be exported and was due to be renewed on November 19.
On Saturday Russia announced its suspension in the grain agreement after accusing Kyiv of a "massive" drone attack on the Black Sea Fleet near Sevastopol.
Ukraine has neither denied nor confirmed it was behind the attack while Ukrainian military suggested that Russians themselves may have been responsible for the explosions.
Ukraine's foreign minister said on Twitter that Russia was blocking "two million tons of grain on 176 vessels already at sea" that he said was "enough to feed seven million people."
He accused Moscow of having planned to "resume its hunger games" in advance and said the Black Sea explosions were "220 kilometers away from the grain corridor."
Russia's defense ministry alleged Sunday the attack drones had "Canadian-made navigation modules," saying it had recovered debris from some of the weapons in the sea. There has been no third party verification of this claim.
Moscow also asserted that British navy "specialists" had helped coordinate what it called a terrorist attack. Britain denied the claim.
Moscow asked the U.N. Security Council to meet on Monday to discuss the Sevastopol attack, Deputy U.N. Ambassador Dmitry Polyanskiy wrote on Twitter.
US President Joe Biden called Russia's effective grain stoppage "purely outrageous" while Secretary of State Antony Blinken said Moscow was "weaponing food."
Wheat prices on international commodities markets are expected to soar on Monday as a result, analysts said.
For hungry countries in Africa, the market's action mean even more depleted national financial resources. As well as the shipping halt preventing desperately needed food from getting to the continent.
EU Foreign Policy Chief Josep Borrell said Sunday he and UN SecGen Guterres had spoken on coordinating action to keep exports flowing from Ukraine, adding "Russia must go back to agreement."
This report was prepared using data from Reuters and Agence France-Presse.