UNITED NATIONS, United States -- UN chief Antonio Guterres warned Monday that the world must act to prevent a "hurricane of hunger and a meltdown of the global food system" following Russia's invasion of Ukraine.

The secretary-general told reporters in New York that the war risks sparking far-reaching consequences for the global food supply that will have a devastating impact on the poorest.

"This war goes far beyond Ukraine. It is also an assault on the world's most vulnerable people and countries," Guterres said.

Even before the war, he said, developing countries were "struggling to recover from the pandemic -- with record inflation, rising interest rates and looming debt burdens."

"Now their breadbasket is being bombed," Guterres said, noting that Ukraine provides more than half of the World Food Programme's wheat supply.

He warned that the UN's global food prices index is at its highest level ever and that the world's 45 least developed countries import at least one-third of their wheat from Ukraine or Russia.

They include Burkina Faso, Egypt, the Democratic Republic of Congo, Lebanon, Libya, Somalia, Sudan and Yemen.

"We must do everything possible to avert a hurricane of hunger and a meltdown of the global food system," Guterres implored, calling for an immediate end to hostilities.

The secretary-general was speaking on the sidelines of a briefing by the Organization for Security and Cooperation in Europe (OSCE) to the Security Council.

The foreign minister of Poland, which holds the rotating presidency of the OSCE for 2022, said Russia's invasion of Ukraine had been "a strategic and tactical failure."

Zbigniew Rau said that, as a result, Moscow changed its tactics to start targeting civilians.

"This is deplorable and shameful and amounts to state terrorism," he added.

Rau said that Russia's aggression "threatens the very existence of the OSCE," but added he would soon travel to Moldova and the Balkans to "prove OSCE's engagement" in helping end the war.