The Justice Department said that when he left the White House in January 2021, Trump took with him highly classified files from the Pentagon, CIA, National Security Agency and other intelligence bodies.

Trump kept them unsecured at his Mar-a-Lago residence and club in Florida, which regularly hosted large social events involving tens of thousands of guests, according to the indictment filed in federal court in Florida.

And at least on two occasions, Trump showed classified documents on US military operations and plans to people not cleared to see them at his Bedminster, New Jersey golf club.

The documents Trump took "included information regarding defense and weapons capabilities of both the United States and foreign countries, United States nuclear programs; potential vulnerabilities of the United States and its allies to military attack; and plans for possible retaliation in response to a foreign attack," the indictment said.

"The unauthorized disclosure of these classified documents could put at risk the national security of the United States," it said.

Trump was charged with 37 counts including willful retention of national defense information, conspiracy to obstruct justice, corruptly concealing documents, and false statements.

The charges, brought by Justice Department Special Counsel Jack Smith, bring up to 20 years in prison each.

A Trump aide, Walt Nauta, was charged with six counts for helping Trump hide the documents.