The U.S. Treasury Department said Thursday it's notified the Delaware-based Heritage Trust that it's blocking more than $1 billion in assets linked to the sanctioned Russian oligarch Suleiman Kerimov.

Why it matters: The U.S. and other governments are intensifying efforts to financially squeeze oligarchs with ties to Russian President Vladimir Putin due to the invasion of Ukraine.

Driving the news: "Heritage Trust was formed in July 2017 for the purpose of holding and managing Kerimov's U.S.-based assets," per a Treasury Department statement.

• "Kerimov has retained a property interest in Heritage Trust following his designation, which results in Heritage Trust being blocked," the U.S. Treasury said.
• Kerimov's nephew Ruslan Gadzhiyevich Gadzhiyev, whom the U.S. sanctioned in March, has been a beneficiary of the trust and "his continuing property interest in Heritage Trust provides a separate and independent basis for Heritage Trust to be blocked," according to the department.

By the numbers: The Treasury Department announced Wednesday that a multinational task had blocked or frozen more than $30 billion worth of sanctioned Russians' assets and funds.

The big picture: The U.S. Treasury has designated Kerimov, a member of the upper house of Russian parliament with links to Putin, as an official in the Russian government and sanctioned him in 2018 for alleged money laundering and tax evasion both in the United States and the European Union.

• A seized superyacht that U.S. officials say is linked to Kerimov arrived in San Diego Bay this week and will remain in the custody of the U.S. government, pending its anticipated forfeiture and sale, according to the Justice Department.

What they're saying: "Treasury continues using the full range of our tools to expose and disrupt those who seek to evade our sanctions and hide their ill-gotten gains," Treasury Secretary Janet Yellen said in a statement.