Biden Warns Putin to Act on Ransomware Groups or Face Retaliation

President Biden warned President Vladimir V. Putin of Russia that time was running out for him to rein in the ransomware groups striking the United States, telegraphing that this could be Mr. Putin’s final chance to take action on Russia’s harboring of cybercriminals before the United States moved to dismantle the threat. In Mr. Biden’s starkest warning yet, he conveyed in a phone call to Mr. Putin that the attacks would no longer be treated only as criminal acts, but as national security threats — and thus may provoke a far more severe response, administration officials said.