The US Treasury Department says it has frozen the assets of 21 entities and 13 individuals as part of efforts to crack down on networks that have been set up to evade sanctions against Russia.

The department said in a statement on Thursday the list includes a Moscow-based company that procures military equipment and technology. It said the company is at the center of a network.

The statement said the Russian military and intelligence agency rely on western technology, and are using the network that operates across multiple countries to obfuscate end-users.

The list also includes Russia's largest chipmaker.

Last month, the department imposed sanctions on state-run companies and individuals that directly support Russia's military operations in Ukraine.

US Secretary of State Antony Blinken said in a statement that "we will continue to target President Putin's war machine with sanctions from every angle, until this senseless war of choice is over."