The CEO of CBS News, one of America's best-known broadcast media outlets, quit Monday citing a "challenging" last few months as the network became embroiled in legal and business tensions with the Trump administration.

U.S. President Donald Trump is suing CBS owner and media giant Paramount for $20 billion in damages over the contents of a pre-election interview last year with his Democratic rival, Kamala Harris.

Legal experts have argued the lawsuit is baseless, and would be an easy legal victory for CBS if it ever went to court, per constitutional protections for freedom of the press.