The US has imposed a string of new sanctions on individuals linked to Russia, including a woman alleged to be Vladimir Putin’s girlfriend.
Alina Kabaeva, a former Olympic gymnast the US has described as having a “close relationship” with Putin, was among the individuals and companies sanctioned.
The US Treasury said in a statement that Ms Kabaeva heads the National Media Group, a pro-Kremlin group of media organisations.
Putin has denied news reports that they are romantically linked. The UK sanctioned Kabaeva in May.
Andrey Grigoryevich Guryev, a business tycoon who is a “known close associate” of Putin’s was also among those placed on the sanctions list, said the US, which means assets are blocked and US citizens are generally prohibited from dealing with them.
US officials said Mr Guryev owns the Witanhurst Mansion in Highgate, which is “the second-largest estate in London after Buckingham Palace”.
They also named a Cayman Islands-flagged yacht, the Alfa Nero, as the “blocked property” of Mr Guryev.
The latest round of sanctions also targets MMK, one of the world's largest steel producers, because it is one of Russia’s largest taxpayers and provides substantial revenue to the Russian government.
The Trade Department also announced sanctions against other individuals, as well as a financial institution accused of running a sanctions evasion operation.
Separately, the US State Department said Tuesday it was placing visa restrictions on 893 Russian officials and members of the military for playing a role in actions against Ukraine, as well as 31 foreign officials from unnamed nations over support for Russia's annexation of Crimea.
It said it would be sanctioning 24 Russian defence and technology companies, and three Russian businessmen the State Department accused of being "Putin enablers”.
Secretary of State, Antony Blinken, said: “The United States will not waver in its support for the brave people of Ukraine and will continue to promote accountability for President Putin and his cronies whose actions have caused so much suffering and destruction in Ukraine”.
The Kremlin has long denied that Putin, who is divorced, is romantically involved with Ms Kabaeva.
Ms Kabaeva won gold in the 2004 Olympics in Athens.