CNN reported that former US president Donald Trump was detained at a federal courthouse in Florida on Tuesday and pleaded not guilty to federal criminal charges that he unlawfully retained national security documents after leaving office and lied to officials who attempted to recover them.

Deputy marshals booked and fingerprinted the former president, while his aide and co-defendant, Walt Nauta, was also apprehended, fingerprinted, and processed.

Trump's guilty plea, entered before US Magistrate Judge Jonathan Goodman in a federal court in Miami, sets the stage for a legal battle that will likely play out over the next few months as he campaigns to regain the presidency in the November 2024 election.

The hearing was closed to live broadcasts and cameras.

It was Trump's second court appearance in recent months. In April, he pled not guilty in New York to state charges arising from a hush-money payment to a pornstar.

Trump is the first former president to face federal criminal charges.

Trump has repeatedly asserted his innocence and accused the administration of Democratic President Joe Biden of targeting him.

Tuesday, he referred to Special Counsel Jack Smith, overseeing the prosecution, as a "Trump hater" on social media.