LONDON — Britain and the United States blamed the Russian government on Thursday for a cyberattack that hit businesses across Europe last year, with London accusing Moscow of “weaponizing information” in a new kind of warfare.

Foreign Minister Tariq Ahmad said “the U.K. government judges that the Russian government, specifically the Russian military, was responsible for the destructive NotPetya cyberattack of June 2017.”

The fast-spreading outbreak of data-scrambling software centered on Ukraine, which is embroiled in a conflict with Moscow-backed separatists in the country’s east. It spread to companies that do business with Ukraine, including U.S. pharmaceutical company Merck, Danish shipping firm A.P. Moller-Maersk and FedEx subsidiary TNT.

The White House joined with British leaders, saying the Russian military had “launched the most destructive and costly cyber-attack in history.” President Donald Trump’s administration said the move was part of the Kremlin’s attempt “to destabilize Ukraine and demonstrates ever more clearly Russia’s involvement in the ongoing conflict.”

“This was also a reckless and indiscriminate cyberattack that will be met with international consequences,” said White House press secretary Sarah Huckabee Sanders.

Ahmad said the “reckless” attack cost organizations hundreds of millions of dollars.

British Defense Secretary Gavin Williamson accused Russia of “undermining democracy, wrecking livelihoods by targeting critical infrastructure, and weaponizing information” with malicious cyberattacks.

“We must be primed and ready to tackle these stark and intensifying threats,” Williamson said.

Danish defense minister Claus Hjort Frederiksen said intelligence agencies in Britain, Denmark and elsewhere had uncovered the Russian responsibility.

Speaking at a NATO defense ministers’ meeting in Brussels, he said the hack was meant to cause damage and should “be compared with a military attack.”

President Vladimir Putin’s spokesman, Dmitry Peskov, denied Russia’s involvement.

“We categorically deny the accusations. We consider them unfounded and baseless and see them as continuation of groundless Russophobic campaign,” he told reporters.


Jan M. Olsen in Copenhagen, Denmark, Vladimir Isachenkov in Moscow and Ken Thomas in Washington contributed to this story.