President Joe Biden on Thursday met with Russian opposition leader Alexei Navalny’s widow, Yulia Navalyana, and his daughter, Dasha, in California on Thursday.

Navalny, 47, an anti-corruption crusader who antagonized Russian President Vladimir Putin for years, died last week in an Arctic penal colony 1,200 miles northeast of Moscow. Russian authorities said he collapsed while on a walk, but have yet to announce a cause of death.

Navalny’s family members and supporters in Europe and the U.S. have laid blame for his demise at Putin’s feet. Yulia Navalyana vowed to carry on his work.

Biden wrote in a post on X, formerly Twitter, that he met with Navalny's loved ones "to express my condolences for their devastating loss."

Navalny's "legacy of courage will live on in Yulia and Dasha, and the countless people across Russia fighting for democracy and human rights," Biden added.

President Joe Biden meets with Alexei Navalny's widow, Yulia Navalyana, and his daughter, Dasha, in San Francisco, Calif., on Thursday, Feb. 22, 2024. (Twitter / POTUS)

According to the White House, Biden “expressed his admiration” for Navalny’s “extraordinary courage and his legacy of fighting against corruption and for a free and democratic Russia in which the rule of law applies equally to everyone” and said that his “legacy will carry on through people across Russia and around the world mourning his loss and fighting for freedom, democracy, and human rights.”

Biden also assured them that his administration on Friday "will announce major new sanctions against Russia" on Friday in response to Navalny's death, as well as for "Russia’s repression and aggression, and its brutal and illegal war in Ukraine."

Speaking to reporters later Thursday, Biden called the meeting an "honor" and reiterated who he believes is to blame for Navalny's demise: "We are going to announce sanctions against Putin who is responsible for his death tomorrow."

"We are not letting up," he pledged, according to the White House pool.

Spectrum News' Joseph Konig and Maddie Gannon contributed to this report.