Kobre & Kim and two of its attorneys, Michael Kim and Michael Sherwin, registered with the US Justice Department to represent Abramovich on “government relations strategy” and “judicial and administrative proceedings”.

The legal rates will range from $875 to $1,900 an hour, according to a filing this week under the Foreign Agents Registration Act.

The registration comes after the Russian invasion of Ukraine prompted many US law firms to drop clients in Russia. The UK and European Union sanctioned Abramovich, who has longtime ties to Russian President Vladimir Putin.

Last month, a US judge signed a warrant for seizure of a Boeing 787-8 Dreamliner and a Gulfstream G650ER that the US says Abramovich owns or controls.

Abramovich (55) has managed to escape US sanctions because of his role as an informal mediator trying to broker peace talks during the war between Russia and Ukraine. He got involved in peace talks at the request of Ukrainian President Volodymyr Zelensky.

“Kobre & Kim is pleased to offer its assistance in matters of legal importance to ensure the law is fairly applied,” Michael Kim, the firm’s co-founder, said in a statement. Because of Abramovich’s involvement in peace talks and humanitarian efforts, “a due and fair process in relation to any legal or administrative matters is essential to ensure his efforts are not hindered”.

Abramovich denies he has financial links to the Kremlin. He’s one of the richest people in Russia and sold the Chelsea Football Club this year under pressure from UK sanctions.

The Wall Street Journal first reported the Foreign Agents Registration Act filing by Kobre & Kim.

(Reporting by David Voreacos and Stephanie Baker.)