Meat processing giant JBS S.A. told U.S. officials Tuesday that it was hit by a ransomware attack that likely came from Russia. The incursion forced JBS to shut down all of its plants in the United States, though it later said it expected the “vast majority” of them to resume operations Wednesday. “JBS notified the administration that the ransom demand came from a criminal organization likely based in Russia,” White House principal Deputy Press Secretary Karine Jean-Pierre said. “The White House is engaging directly with the Russian government on this matter, and delivering the message that responsible states do not harbor ransomware criminals.”

The shutdown raises concerns about food security, as JBS is the world’s largest supplier of meat. Within the U.S., JBS sources about a quarter of all beef, and a fifth of all pork. Beef prices had already spiked last month across the world due to supply chain disruptions, and further delays from JBS may increase prices further. Earlier this month, a ransomeware attack on Colonial Pipeline left U.S. oil supplies strained.