Calls made with AI-generated voices are illegal, the U.S. Federal Communications Commission (FCC) said on Thursday, after a fake robocall imitating President Joe Biden sought to dissuade people from voting for him in New Hampshire's Democratic primary election.

The declaratory ruling gives state attorneys general new tools to go after the entities behind the robocalls, FCC Chair Jessica Rosenworcel said.

"Bad actors are using AI-generated voices in unsolicited robocalls to extort vulnerable family members, imitate celebrities, and misinform voters. We're putting the fraudsters behind these robocalls on notice," Rosenworcel said.

The FCC noted that state attorneys generals previously could target the outcome of an unwanted AI-voice-generated robocall, but the new action makes the act of using AI to generate a voice in these robocalls itself illegal.

Earlier this week, New Hampshire Attorney General John Formella said the fake Biden robocall has been traced back to Texas-based Life Corp. He said a cease-and-desist letter has been sent to the company, run by Walter Monk, and a criminal investigation is under way.

"The use of generative AI has brought a fresh threat to voter suppression schemes and the campaign season with the heightened believability of fake robocalls," Democratic FCC Commissioner Geoffrey Starks said.

"Voice cloning," the FCC said, "can convince a called party that a trusted person, or someone they care about such as a family member, wants or needs them to take some action that they would not otherwise take."

The FCC in 2023 finalized a $5.1 million fine levied on conservative activists for making more than 1,100 illegal robocalls ahead of the 2020 U.S. election.

The calls sought to discourage voting by telling potential voters that if they voted by mail, their "personal information will be part of a public database that will be used by police departments to track down old warrants and be used by credit card companies to collect outstanding debts."