The White House blamed Russia on Friday for this week's cyberattacks targeting Ukraine's defense ministry and major banks and warned of the potential for more significant disruptions in the days ahead.

Anne Neuberger, the Biden administration's deputy national security adviser for cyber and emerging technologies, said the U.S. had rapidly linked Tuesday's attacks to Russian military intelligence officers. 

Britain joined the U.S. in blaming the GRU military intelligence agency for the distributed denial-of-service attacks that unfolded as tensions escalate between Russia and Ukraine.

The attacks, which knocked government websites and a couple of major banks offline for much of the day, were of "limited impact" since Ukrainian officials were able to quickly get their systems back up and running, Neuberger said. 

But she said the Russians could also be laying the groundwork for more disruptive activities that could accompany an invasion of Ukraine.

"We do expect that should Russia decide to proceed with a further invasion of Ukraine, we may see further destabilizing or destructive cyber activity, and we've been working closely with allies and partners to ensure we're prepared to call out that behavior and respond," Neuberger said.

She said the U.S. was publicly blaming the Kremlin because of a need to "call out the behavior quickly."

"The global community must be prepared to shine a light on malicious cyber activity and hold actors accountable for any and all disruptive or destructive cyber activity," Neuberger said.

The British Foreign Office said the attack "showed a continued disregard for Ukrainian sovereignty. This activity is yet another example of Russia's aggressive acts against Ukraine."

Neuberger said there was no intelligence indicating that the U.S. would be targeted by a cyberattack, but that remained a concern, given that the banking system does not have the "cyber resilience" that it should.

Ukrainian officials called Tuesday's attacks the worst in the country's history. But while they definitely disrupted online banking, impeded some government-to-public communications and were clearly intended to cause panic, they were not particularly serious by global or historic standards, said Roland Dobbins, the top engineer for DDoS at the cybersecurity firm Netscout.

"Most DDoS attacks succeed due to the lack of preparation on the part of the defenders," said Dobbins, adding that most commercial mitigation services designed to counter such attacks would likely have been able to fend off Tuesday's attacks.

This story was originally published by Willie James Inman and Rob Nelson of Newsy, the Associated Press contributed.

MOSCOW —

“Wars in Europe rarely start on a Wednesday.”

That’s how a top Russian diplomat brushed off speculation in the West that Russia could invade neighboring Ukraine as soon as Wednesday, Feb. 16.

As the U.S. and other NATO members warn of the potential for a devastating war, Russia is not countering with bombs or olive branches — but with sarcasm.

It’s a tool that officials in Moscow have long used to belittle their rivals and to deflect attention from actions seen as threatening to the West or Russia’s neighbors. Laconic quips dovetail with the Kremlin’s domestic agenda by making Russia and its all-powerful president look more cool-headed and clever than countries in the panicky, democratic West.

As worries mushroomed that Wednesday could be the day President Vladimir Putin launches an invasion of Ukraine, Russian officials ridiculed them.

In a Facebook post, Foreign Ministry spokesperson Maria Zakharova asked the “mass media of disinformation” in the West “to reveal the schedule of our ‘invasions’ for the upcoming year. I’d like to plan my vacations.”

“To the regret of many Western media, the war again failed to start,” Zakharova said at a briefing on Wednesday. “Fighting has erupted on their pages, but it has no relation to reality.”

Ukrainians, meanwhile, have been living amid signs of a possible invasion for several weeks, with an estimated 150,000 Russian troops surrounding much of their country for military exercises. Russia said this week it was starting to pull back some troops, but Western military officials say there's no evidence of a serious withdrawal.

Russia’s ambassador to the European Union, Vladimir Chizhov, accused Westerners of “slander” for alleging an invasion was afoot. He insisted in an interview with German daily newspaper Welt that “there won’t be an attack this Wednesday.”

Then Chizhov added: “Wars in Europe rarely start on a Wednesday.’”

The statement seemed more flippant than historically significant. World War I started on a Tuesday and World War II started in Europe on a Friday, but Europe's history of war over centuries includes conflicts that kicked off throughout the week.

Kremlin spokesman Dmitry Peskov also took the West's growing fears lightly. Asked Wednesday whether Russia's presidential administration operated differently overnight, he told reporters that everyone slept calmly and resumed work in the morning as usual.

“Western hysteria is still far from its culmination,” Peskov said. "We need to have patience, as the remission will not come quickly.”

The master of Russian diplomatic snark is Foreign Minister Sergey Lavrov. He is known worldwide for his quips – often said in English — over 18 years as the Kremlin’s top diplomat.

On Wednesday, Lavrov mocked the West as sadly "lacking basic upbringing” for trying to dictate or predict Russia’s plans.

Beneath the sarcasm, Russia has narrated the current Ukraine crisis from the outset: first by moving troops toward Ukraine, then by periodically holding out the possibility of a diplomatic solution, keeping foreign officials and global markets on constant edge.

While Putin offered more talks this week, his intentions in Ukraine remain unclear. Western intelligence suggests an invasion of some kind could still happen – on a future Wednesday or any day of the week.