(Bloomberg) -- Russia pulled out of a deal to allow Ukrainian grain exports from Black Sea ports after drone strikes against its naval vessels, a move that threatens to exacerbate the global food crisis and send prices soaring again.

“It’s purely outrageous,” US President Joe Biden told reporters in Delaware. “It’s going to increase starvation.”

Saturday’s move came hours after Russia said Ukraine carried out an attack on its Black Sea fleet off Sevastopol, Crimea. Ukraine hasn’t confirmed its participation in the drone-led strike, but called for “tough international reaction” to Russia’s decision.

Russia has a pattern of retaliating against strikes on Crimea, which was annexed by Vladimir Putin in 2014. Kremlin forces unleashed a barrage of attacks against Ukraine’s power grid and other key infrastructure following the previous high-profile strike attributed to Ukraine, an explosion on the Kerch Strait Bridge between mainland Russia and Crimea.

Russia’s Foreign Ministry called suspending the grain deal “indefinite,” dimming the prospect for talks to extend the agreement beyond its initial Nov. 19 end date. Brokered in July by the United Nations and Turkey, the safe-passage accord has been crucial in allowing the flow of millions of tons of grain that had piled up in Ukraine since Russia’s invasion, in addition to new crops being harvested.

In his regular nightly address to the nation, Ukrainian President Volodymyr Zelenskiy said about 170 vessels are currently stranded, with some of them waiting for more than three weeks. That, he said, means more than 2 million tons of food is at sea. 

“This is an absolutely deliberate blockade by Russia,” Zelenskiy said. “This is an absolutely transparent intention of Russia to return the threat of large-scale famine to Africa and Asia.”

Eight months after Russia invaded its neighbor, the war is taking an even crueler turn with winter just weeks away. Millions of Ukrainians are without power because of rolling blackouts due to Russia’s bombing campaign, Iran is supplying armed drones to Putin’s forces and Russian officials have claimed -- in comments rejected by Kyiv -- that Ukraine is planning a “dirty bomb.”

But pulling the plug on a deal regarded as a vital step to ease the global food crisis threatens to extend the conflict’s significance deeper beyond Europe.

Condemnation was swift from Ukraine’s allies. 

“They’re always looking for some rationale to be able to say the reason they’re doing something outrageous is because the West made them do it,” Biden said. “There’s no merit to what they’re doing. The UN negotiated that deal and that should be the end of it.”

Putin has repeatedly complained about the deal, saying not enough shipments were being sent to poor nations. Russia has also said its own grain and agricultural goods were not being allowed the same access to global markets.

However, claims that developing nations aren’t benefiting from the safe-corridor deal aren’t backed up by data, which show a considerable segment of the shipments have gone to these countries. 

Farmers and grain traders have been anxiously watching the discussions. Forward sales were already drying up on worries that the agreement would lapse, and Ukraine had also raised concerns about a growing backlog of ships waiting for inspection as part of the agreement.

Market Shock

A prolonged suspension could once again send shocks through global crop markets. While grain prices have eased in recent months, the soaring dollar has left importers struggling to make payments and raising the threat of shortages.

To be sure, Ukraine is also exporting crops by land and river, but the safe-passage deal has been crucial in significantly increasing the flow of grain from one of the world’s most important producers. More than 9 million tons of goods have left Ukrainian Black Sea ports since the first vessel sailed Aug. 1.

Moscow also sought to finger Ukraine’s Western allies for its pretext to suspending the deal. It accused “British specialists” of helping the attacks on the Black Sea fleet, which the UK defense ministry called “false claims on an epic scale.”  

Russia earlier said the vessels targeted were involved in ensuring security for the Black Sea grain initiative, a claim that can’t be verified. Moscow said there had been only minor damage to a navy minesweeper.

--With assistance from Liezel Hill and Daryna Krasnolutska.

(Updates with Biden comment starting second paragraph.)

©2022 Bloomberg L.P.