"The US government believes that Russian cyber actors likely have targeted the Ukrainian government, including the military and critical infrastructure networks to collect intelligence and prepositioned to conduct disruptive cyber activities," Neuberger said during a press briefing.
Neuberger said the United States has shared intelligence with Ukraine and its European partners about the cyber activity. The United States also believes Russia is behind the recent cyberattack against major banks in Ukraine, she added.
Moreover, she added that the Biden administration is ready to respond to potential asymmetric activities from Russia such as cyber attacks on the United States or its allies.
"As the President said earlier this week, if Russia attacks the United States or allies through asymmetric activities like disruptive cyber attacks against our companies or critical infrastructure, we are prepared to respond," Neuberger said.
On Tuesday, the websites of Ukraine's defense ministry, armed forces and two major banks were hit by a cyberattack.
Russia has repeatedly dismissed allegations of involvement in state-run cyber campaigns. Last month, Kremlin spokesman Dmitry Peskov said in an interview with CNN’s Fareed Zakaria that claims of Russian involvement in the cyberattacks against Ukrainian government websites are groundless.
"We have nothing to do with it. And Russia has nothing to do with these cyber attacks. We have heard accusations against Russia …not a proof was presented and we consider it a continuation of another unproven accusation against Russia. We are nearly accustomed to the fact that Ukrainians are blaming everything on Russia, even their bad weather," Peskov told the host in mid-January.
Back then, after the cyberattack against several Ukrainian government websites, US National Security Advisor Jake Sullivan said that this was "a relatively unsophisticated attack" and Washington believed that some of the claims that were made on the Ukrainian government websites when they were hacked were far-fetched.
Sanctions Prepared to Deny Foreign Capital to Russia in Event of Ukraine 'Invasion', White House Says
Also on Friday, US Deputy National Security Advisor Daleep Singh stated that the West is planning to deprive Russia of access to global financial markets and advanced technologies if Moscow decides to "invade" Ukraine.
"We're also prepared to impose powerful export controls as part of our response package. Both financial sanctions and export controls deny something to Russia that it needs and can't get from anywhere other than the United States or our allies and partners. Financial sanctions deny foreign capital to Russia, and export controls deny critical technological inputs that Russia needs to diversify its economy," Singh said during a press briefing.
Singh added that US financial sanctions have been designed to impose "overwhelming and immediate" costs on the largest financial institutions and state-owned enterprises in Russia.
"All options remain on the table, but it’s probably not going to be the case that you’ll see SWIFT in the initial rollout package. We have other severe measures we can take that our allies and partners are ready to take in lockstep with us that don’t have the same spillover effects" Singh also said.
The Russia sanctions package is being finalized and coordinated with US allies and partners, he noted.