The US imposed sanctions on four Russian tycoons who helped found the Alfa Group banking conglomerate, finally joining UK and European allies that had restricted their assets soon after the Ukraine war began.

The Treasury Department announced sanctions against Mikhail Fridman, Petr Aven, German Khan and Alexey Kuzmichev, partners in the group that controls Russia’s largest retailer and private bank. The four had been sanctioned for more than a year in Europe and have been challenging their designations in a series of legal actions.

“Wealthy Russian elites should disabuse themselves of the notion that they can operate business as usual while the Kremlin wages war against the Ukrainian people,” Deputy Secretary of the Treasury Wally Adeyemo said in a statement. “Our international coalition will continue to hold accountable those enabling the unjustified and unprovoked invasion of Ukraine.”

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It had been an enduring mystery why the US — which has slapped sanctions on hundreds of people and entities over the war — had held off punishing the four for so long given the allegations against them. When it imposed sanctions, the EU called Aven “one of Vladimir Putin’s closest oligarchs,” while the UK said Fridman was an “enabler” of the Russian president’s inner circle. The men have denied those claims.

In Friday’s announcement, the US also included sanctions on the Russian Union of Industrialists and Entrepreneurs, a business organization it said has organized meetings to promote responses to sanctions and promoted substitutions for imports of sanctioned goods. Fridman was sanctioned in part for allegedly having acted on behalf of the group.

“The new designations are sending a message to the Russian high net worth individuals everywhere — if you do not openly condemn the Russian invasion it would not be possible to carry out business as usual,” said Vita Spivak, an analyst at Control Risks, a global risk and strategic consulting firm.

Read more: How an Ex-Goldman Banker Fought US Sanctions Over Russia and Won

Fridman has publicly condemned the war as a “tragedy,” saying “war can never be the answer,” but he stopped short of directly criticizing Putin. One of Russia’s most prominent businessmen, Fridman and his partners have told the courts there’s no evidence he’s a Putin ally or that he’s backed or benefited from aggression in his native Ukraine.

Latvia is weighing whether to revoke Aven’s citizenship, which he acquired in 2016. The sanctions are “another important signal to the responsible Latvian institutions evaluating the legitimacy of his citizenship,” Prime Minister Krisjanis Karins said on the social-media platform X.

Other wealthy Russians have managed to get sanctions against them lifted. Most recently, Russia-born billionaire Oleg Tinkov was removed from UK sanctions list. Tinkov, who gave up citizenship after criticizing the invasion of Ukraine, was sanctioned by the UK authorities for his alleged ties to the Russian government, in particular through Tinkoff Bank.

--With assistance from Aaron Eglitis.

(Updates with details of sanctions in second paragraph.)