"Almost all the grain exported from Ukraine is sent not to the poorest developing countries, but to EU countries," Putin told the Eastern Economic Forum in Russia's Pacific port city of Vladivostok.
Ukraine, one of the world's largest grain exporters, was forced to halt almost all deliveries after Russia started a military operation in late February.
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Exports of grain across Black Sea ports resumed after Kyiv and Moscow in July inked a deal with the United Nations and Turkey acting as guarantors.
"We did everything to ensure that Ukrainian grain was exported... we did it together with Turkey," Putin said at the forum.
Putin said European countries "acted as colonialists in recent decades and centuries" and "they continue to act so today".
He said they "once again simply deceived developing countries".
"With this approach, the scale of food problems in the world will only grow," Putin said, adding that it could lead to "an unprecedented humanitarian catastrophe".