Ukrainian President Volodymyr Zelensky has called Africa "a hostage" of Russia's war during an address to the African Union (AU) on Monday.
Russia's invasion, and its blockade of Ukraine's grain exports, have sparked grain and fertiliser shortages and put millions of people at risk of hunger.
The chair of the AU commission said there was an "urgent need for dialogue" to restore global stability.
Western countries have urged Russia to release Ukraine's vast grain stores.
The blockade has sent food prices soaring.
"Africa is actually a hostage... of those who unleashed war against our state", Mr Zelensky said in his speech.
Earlier on Monday, EU foreign policy chief Josep Borrell said of Russia's blockade: "This is a real war crime, so I cannot imagine that this will last much longer."
Mr Borrell met EU foreign ministers in Luxembourg on Monday to discuss the crisis.
He described Moscow's actions as "a deliberate attempt to create hunger in the world".
He rejected Russia's claim that the current food crisis is a result of EU sanctions, adding that they "don't forbid" countries outside the EU from conducting food trade with Russia or other nations.
French Foreign Minister Catherine Colonna said that "Russia must stop playing with global hunger" as it seeks leverage over the West.
"Leaving cereals blocked is dangerous for stability in the world," she said.
The head of the Polish prime minister's office, Michal Dworczyk, spoke with Ukraine's infrastructure minister Oleksandr Kubrakov about changes that will speed up checks for trucks on the Polish-Ukrainian border to help export more grain from Ukraine.