U.S. President Joe Biden says he has warned Russian President Vladimir Putin that the days of the United States “rolling over” with regard to Russia’s transgressions have ended.

“I made it clear to President Putin, in a manner very different than my predecessor, that the days of the United States rolling over in the face of Russia’s aggressive actions — interfering with our elections, cyberattacks, poisoning its citizens — are over,” Biden said on February 4 in a speech to the State Department in Washington during his first visit to the country’s diplomatic nerve center.

He also urged Russia to release opposition leader Aleksei Navalny, adding: “We will not hesitate to raise the cost to Russia.”