Former President Donald Trump has pleaded not guilty to federal charges alleging he hoarded classified documents detailing sensitive military secrets and schemed to thwart government efforts to get them back.

Trump appeared before a judge in Miami’s federal courthouse on Tuesday in a stunning moment in American history days after he became the first former president charged with federal crimes.

Authorities say Trump schemed and lied to block the government from recovering the documents concerning nuclear programs and other sensitive military secrets stored at his Mar-a-Lago estate.

It’s the second criminal case Trump is facing as he seeks to reclaim the White House in 2024. He’s also accused in New York state court of falsifying business records related to hush-money payments made during the 2016 campaign.

Trump has denied wrongdoing in both cases and slammed the prosecutions as politically motivated. He’s expected to return later Tuesday to New Jersey, where he’s scheduled a press event to publicly respond to the charges.