UN Secretary-General António Guterres has warned of a "hurricane of hunger" around the world because of the Ukraine war.
The international community must act to prevent a "collapse of the global food system".
The war in Ukraine is "also an attack on the most vulnerable people and countries in the world," Guterres said, citing Ukraine's importance as a food exporter.
Even before the war, developing countries were struggling with the consequences of the pandemic, such as inflation, rising interest rates and debt.
"Now their granary is being bombed," Guterres said.
More than half of the World Food Program's wheat shipments come from Ukraine.
According to UN calculations, global food prices have reached their highest level ever.
The world's 45 least developed countries would import at least a third of their wheat from Ukraine or Russia.
These include, for example, Burkina Faso, Egypt, the Democratic Republic of the Congo, Lebanon, Libya, Somalia, Sudan and Yemen.
In many of them, millions of people are already suffering from hunger.