US President Joe Biden has said he is "looking" at possible retaliation after the FBI and the White House linked Russia to a cyber attack against global meat processing giant JBS.

Asked by a reporter if he would take action against President Vladimir Putin, whom he will meet for a summit in Geneva later this month, Mr Biden said: "We're looking closely at that issue."

The ransomware attack on a US subsidiary of Brazilian-owned JBS has again prompted accusations that Russia is at least harbouring cybercriminals.

Similar suspicions were raised after ransomware hackers forced the temporary shutdown of the huge Colonial fuel pipeline in the eastern United States last month.

Asked if Mr Putin is testing him ahead of their summit, Mr Biden said "no."

The Federal Bureau of Investigation yesterday attributed the attack to "REvil and Sodinokibi," which experts have said are two names for the same hacking group with ties to Russia, and said it was "working diligently to bring the threat actors to justice".

"We continue to focus our efforts on imposing risk and consequences and holding the responsible cyber actors accountable," the FBI said in a statement.

The White House said Mr Biden will bring up US concerns during the summit on 16 June, as well as at earlier summits with allies in the G7 group, the European Union and NATO.

"We expect this to be an issue of discussion throughout the president's trip," White House Press Secretary Jen Psaki told reporters.

"Harbouring criminal entities that are intending to do harm, that are doing harm to the critical infrastructure in the United States, is not acceptable," she said.

"We're not going to stand by that. We will raise that and we're not going to take options off the table."

The White House has not blamed the Kremlin directly, only suggesting that criminal groups are operating from inside Russia. However, Ms Psaki said "responsible states do not harbour" cybercriminals.

"President Biden certainly thinks that President Putin and the Russian government has a role to play in stopping and preventing these attacks. Hence, it will be a topic of discussion when they meet," she said.

For its part, Russia has said it would be open to any US request for help in investigating the cyberattack.

JBS is a sprawling meat supplier with operations in the United States, Australia, Canada, Europe, Mexico, New Zealand and Britain.

The company said the vast majority of its beef, pork, poultry and prepared foods plants would be operating "at near full capacity" later today.

JBS "is not aware of any evidence at this time that any customer, supplier or employee data has been compromised," it said in a statement late yesterday.

"Given the progress our teams have made to address this situation, we anticipate operating at close to full capacity across our global operations tomorrow (Thursday)," said JBS USA CEO Andre Nogueira.

Cybercriminals also struck a ferry service in the US state of Massachusetts yesterday, disrupting service between several upscale northeastern coastal communities.

The Steamship Authority of Massachusetts reported the ransomware attack, which delayed its ferry service between Cape Cod and the islands of Nantucket and Martha's Vineyard.

"There is no impact to the safety of vessel operations, as the issue does not affect radar or GPS functionality," the company tweeted as it announced the hack.

The cyberattack did partially disrupt the payment system, which moved to cash as the company said its ability to process credit cards was "limited."

The FBI office in Boston had no immediate comment when contacted by AFP.

Also yesterday New York City's train and bus system, the Metropolitan Transportation Authority (MTA), said it was hacked on 20 April.

However, it added that little damage was done and that riders were never at risk.

An audit after the attack uncovered no signs that the operating systems had been affected, or that the hackers accessed information of clients or employees, MTA's technical chief said.