Russia is using food supplies as a weapon with global repercussions, acting the same way as it does in the energy sector, European Commission President Ursula von der Leyen said on Tuesday.
Speaking at the annual World Economic Forum held in Davos, Switzerland, she said "global cooperation" was the "antidote to Russia's blackmail".
"In Russian-occupied Ukraine, the Kremlin's army is confiscating grain stocks and machinery (...) And Russian warships in the Black Sea are blockading Ukrainian ships full of wheat and sunflower seeds," von der Leyen added.
The EU has pledged to open "solidarity channels" with Ukraine - alternative logistics routes to help the country export grain. Agriculture ministers from EU countries meet in Brussels on Tuesday to discuss progress in launching these.
Russia's invasion of Ukraine - and the West's attempt to isolate Moscow as punishment - have sent the price of grain, cooking oil, fertilizer and energy soaring.
The Kremlin said on Monday that it was the West that was responsible for the global food crisis by imposing the severest sanctions in modern history on Russia over the war in Ukraine.