US President Joe Biden has warned his Russian counterpart that Moscow had to "take action" against cybercriminals, the White House said Friday.

In a one-hour phone call, Biden told Russian President Vladimir Putin the US reserves the right to "defend its people and its critical infrastructure."

It comes after a ransomware attack by the REvil hacking group caused chaos to 1,500 US businesses last weekend.

US expects Russia to act 

Biden told reporters on Friday, "I made it very clear to him that the United States expects, when a ransomware operation is coming from his soil even though it's not sponsored by the state, we expect them to act if we give them enough information to act on who that is."

The US believes Russia has failed to act against spy agencies acting out of its territory. Biden said there would be consequences if Russia failed to act. 

The White House said that Biden pushed Putin "to disrupt ransomware groups operating in Russia" as the hacker threat became an urgent US national security problem.

Biden said he was "optimistic" at the end of the conversation. He made clear the US expected Moscow's cooperation on cyberattacks that originate in Russia.

A statement from Putin's office said, "Despite readiness from the Russian side to jointly clamp down on criminal activity in the informational sphere, over the past month no requests have been received from the relevant US departments." 

However, a senior member of the Biden administration told reporters that the US had made multiple requests to Russia through normal diplomatic channels. 

How serious have the cyberattacks been?

In May, an attack on Colonial Pipeline, which provides fuel to half the East Coast of the United States, forced the company to stop its operations cutting fuel supply to some areas.

Colonial Pipeline had to paya $4.4 million (€3.7 million) ransom to get it running again, although the FBI managed to get most of that figure back last month from the dark web.

Another cyberattack on top meat processor JBS SA led to the company paying out $11 million to the hackers and losing millions more after it was forced to halt operations.

jc/rt (AP, dpa, Reuters)