Two U.S. senators say the United States must respond to a widespread cyberattack that U.S. officials say was carried out by Russian hackers who managed to break into the computer networks of multiple U.S. government agencies.

Senator Mitt Romney (Republican-Utah) said the intrusion “demands a response” and what would be expected is a “cyber-response.” But he said he was not sure the United States had the “capability to do that in a way that would be of the same scale or even a greater scale than Russia has applied to us.”

Speaking on December 20 on U.S. broadcaster NBC, Romney also said he was disappointed in President Donald Trump’s reaction to the data breach.

In his first public comments on the incident, Trump on December 19 downplayed the seriousness and impact of the intrusion and cast doubt on whether Russia was to blame.

Romney said Trump “has a blind spot when it comes to Russia” and doesn’t want to recognize Russia as the “extraordinarily bad actor they are on the world stage.”

He added that Russia goes against the United States “on every front” and the administration has “not been serious enough about how damaging an adversary Russia can be.”

‘Russia Acted With Impunity’

Romney said experts on U.S. cybersecurity have determined that the intrusion came from Russia and was very serious and damaging, noting that the hackers got into the agency that’s responsible for U.S. nuclear capacity and research into nuclear weapons.

He also called for a “rethink” at the Department of Defense and other agencies about U.S. cybercabilities — offensive and defensive.

“What this invasion underscores is that Russia acted with impunity,” Romney said. “They didn’t fear what we would be able to do from a cybercapacity. They didn’t think that our defenses were particularly adequate and they apparently didn’t think that we would respond in a very aggressive way.”

Trump’s response to the cyberattack came in a tweet in which he said it was “far greater in the Fake News Media than in actuality” and indicated that the perpetrators may be the Chinese.

The assertion ran counter to comments by Secretary of State Mike Pompeo, who said in an interview on December 18 that the United States “can say pretty clearly” that it was the Russians.

The Kremlin has denied any involvement.

U.S. Senator Mark Warner (Democrat-Virginia) said on December 20 on ABC that the hack could still be going on and that officials had yet to determine its full scope. He backed Romney’s call for retaliation, but he called the hack an invasion “in that gray area between espionage and an attack.”

Warner, the top Democrat on the Senate Intelligence Committee, said Washington needed to make clear to adversaries “that if you take this kind of action we and others will strike back.”

President-elect Joe Biden is deliberating how to respond, incoming White House chief of staff Ron Klain said.

“It’s not just sanctions, it’s steps and things we could do to degrade the capacity of foreign actors to engage in these attacks,” he said on CBS.

But he cautioned that there were still “a lot of unanswered questions about the purpose, nature, and extent of these specific attacks.”

Based on reporting by Reuters, AFP, NBC, CBS, ABC, and The Washington Post