Kyiv on Wednesday said Russia had destroyed 60,000 tons of grain meant for export in overnight strikes around the port of Odesa.
Russia has fired missiles at Ukraine's southern Odesa region for two nights in a row, hitting ports on the Black Sea after backing out of a grain deal that allowed the safe passage of cargo ships.
Ukraine's Agriculture Ministry said "60,000 tons of grain were also destroyed" in the port of Chornomorsk, outside Odesa.
It said the grain was meant to be "sent through the grain corridor 60 days ago."
"The grain infrastructure of international and Ukrainian traders and carriers such as [Ukrainian] Kernel, [Canadian] Viterra and the [French] CMA CGM Group suffered the most," the ministry said.
"The world's food security is once again in danger," it added.
Ukrainian President Volodymyr Zelensky said earlier that Russia was "deliberately targeting the grain deal infrastructure."
On Monday, Moscow refused to extend the UN-brokered grain deal that allowed for critical grain shipments.
Since exiting the deal, the Kremlin has warned of "risks" over the future of grain exports via the Black Sea.
The UN has argued that the world's poorest would "pay the price" of the collapse of the deal and Western countries have deplored Moscow's exit.