JBS SA, the world's largest meat producer, has made "significant progress” to resolve the cyberattack that impacted its global operations and will have the "vast majority” of its plants operational Wednesday.

"Our systems are coming back online and we are not sparing any resources to fight this threat,” JBS USA Chief Executive Officer Andre Nogueira said in a statement late Tuesday.

The cyberattack forced the shutdown of all of JBS’s U.S. beef plants — facilities that account for almost a quarter of American supplies — according to an official with the United Food and Commercial Workers International Union, which represents workers at the company’s plants in the U.S. All other JBS meatpacking facilities in the country experienced some level of disruption, according to the official.