A Russian energy tycoon who is one of Switzerland's richest people has been hit with sanctions by U.S. President Donald Trump.

The U.S. government hit Viktor Vekselberg, estimated by «Forbes» to be the 44th wealthiest person in the world with a more than $14 billion fortune, and six other oligarchs with sanctions, according to a statement on Friday.

The oil and metals oligarch and ally of Russian leader Vladimir Putin has lived in Switzerland for nearly 15 years, where a holding company for many of his investments is based. Vekselberg, who is advised by luminaries such as former Deutsche Bank boss Josef Ackermann, owns a more than one-quarter stake in Russian aluminium firm Rusal, together with partners.

«Corrupt System»

The U.S. accused Russia's government of continuing to occupy Crimea, fomenting violence in Ukraine, feeding weapons to Syrian President Bashar al-Assad, trying to destabilize Western democracies, and cyber hacking.

«Russian oligarchs and elites who profit from this corrupt system will no longer be insulated from the consequences of their government’s destabilizing activities,» U.S. Treasury Secretary Steven Mnuchin said.

A spokesman for Switzerland's finance department said the government would not comment on move on Vekselberg. The sanctions highlight the tightrope that Switzerland and its banks walk when welcoming the ultra-rich: sanctioned individuals effectively become financial pariahs, as those who do business with them face penalties under the U.S. move. 

Faberge Collector

Vekselberg's tenure in Switzerland, which courts the ultra-wealthy with billionaire-friendly flat tax rates, has been rocky: in 2010, he faced criminal charges for stock market abuses in connection with his stake purchased. He was acquitted.

Vekselberg, who moved from Zurich to lower-tax Zug several years ago, is a low-profile presence in the alpine nation. Known for spending his commodity millions on collecting and displaying imperial Faberge eggs, he has snapped up hefty stakes in firms such as Sulzer and Oerlikon through Renova, the Swiss holding company.

Swiss Coterie

At Renova, Vekselberg has surrounded himself with a coterie of once-influential bankers and businessmen including Ackermann, former Siemens Chief Executive Peter Loescher, and ex-Ferrari boss Luca Cordero di Montezemolo. Loescher left in 2016, after two years on Renova's board.

Russian oligarchs including Oleg Deripaska, a Vekselberg business partner turned adversary who has also banked in Switzerland, and the son-in-law of Putin were also slapped with U.S. sanctions. Vekselberg was a guest at Trump's presidential inauguration in Washington last year.