Brazilian company JBS has told the US government that a ransomware attack on the company that disrupted meat production in North America and Australia originated from a criminal organisation likely based in Russia, the White House has said.

JBS, the world's largest meat packer, said last night it had made "significant progress in resolving the cyber attack".

The "vast majority" of the company's beef, pork, poultry and prepared foods plants will be operational today, according to a statement, easing concerns over rising food prices.

The cyber attack followed one last month by a group with ties to Russia on Colonial Pipeline, the largest fuel pipeline in the United States, which crippled fuel delivery for several days in the US southeast.

JBS halted cattle slaughter at all its US plants yesterday, according to union officials. On Monday, the attack caused Australian operations to shut down.

"Our systems are coming back online and we are not sparing any resources to fight this threat," said Andre Nogueira, chief executive of JBS USA.

With North American operations headquartered in Greeley, Colorado, JBS controls about 20% of the slaughtering capacity for US cattle and pigs.

White House spokeswoman Karine Jean-Pierre said the United States contacted Russia's government and that the FBI was investigating.

"The White House is engaging directly with the Russian government on this matter and delivering the message that responsible states do not harbour ransomware criminals," Ms Jean-Pierre said.

The disruption quickly had an impact, industry analysts said.

US meat packers slaughtered 22% fewer cattle than a week earlier and 18% than a year earlier, according to estimates from the US Department of Agriculture. Pork processing was also down.

Prices for choice and select cuts of US beef shipped to wholesale buyers in large boxes each jumped more than 1%, the USDA said.

The USDA contacted several major meat processors to encourage them to keep supplies moving and slaughter additional livestock when possible, according to a statement. The agency also urged meat packers to make their IT and supply-chain infrastructure more durable.

Federal agencies including the USDA and Department of Homeland Security are closely monitoring meat and poultry supplies, a White House official said.

The agencies are also working with agricultural processors to ensure no price manipulation occurs as a result of the cyber attack, the official said.

JBS said Sunday's cyber attack affected its North American and Australian IT systems and "resolution of the incident will take time, which may delay certain transactions with customers and suppliers".