Ukrainian President Volodymyr Zelensky said nearly half of Ukraine’s grain export supply is currently held up as Russia continues to block the country’s main export routes through the Black Sea and Azov Sea, calling the situation a potential “catastrophe” for global food security, News.az reports citing UNIAN.

Addressing an Indonesian foreign policy think tank in an online forum Friday, Zelensky said, “22 million tons of grain are kept in silos today. We cannot supply them to international markets where they are needed at this very point in time."

The Ukrainian president also said the UN estimates that famine might affect additional 50 million people this year were a “conservative” estimate, implying that the number of those affected will be greater.

“Famine doesn’t come alone, it is always accompanied by political chaos that exacerbates the situation, ruins people’s lives, creating unsafe conditions for ordinary people," he said. "In July, when many countries will exhaust their stock of last year’s harvest, it will become obvious the catastrophe is truly coming."