Donald Trump has arrived at a federal court in Miami, Florida, to face historic charges of mishandling sensitive files.
Mr Trump is the first US president – current or former – to be hit with a federal criminal indictment.
He will be spared a mugshot, but is expected to be fingerprinted and give a DNA sample after the hearing.
This is the second time Mr Trump has appeared in court this year, but Tuesday’s case is more serious.
Small crowds of Trump supporters and counter-protesters were outside the Wilkie D Ferguson Jr court in downtown Miami.
Mr Trump, 76, was driven by motorcade from the Trump National Doral resort – where he spent the night – to court for his 15:00 (19:00 GMT) arraignment. Arriving at the court complex, the procession of vehicles drove into an underground garage.
He was booked alongside a close aide, Walt Nauta, who is charged with six criminal counts related to alleged mishandling of national security documents.
During the drive to court, several messages were posted to Mr Trump’s account on the social media platform Truth Social, including one in all capital letters saying: “One of the saddest days in the history of our country. We are a nation in decline!!!”
Appearing before a judge, Mr Trump is expected to deny 37 counts of illegally retaining classified documents and obstructing the government’s efforts to get them back.
After the arraignment he will be processed by the court system. Instead of facing the humiliation of a booking photo, the US Marshals Service – which secures federal courts – will use a previously taken photo of Mr Trump, officials at the court briefed journalists on Tuesday morning.
The hearing will last for about an hour and will address various procedural issues, although it is unlikely a trial date will be set. A judge earlier rejected a request by news organisations to allow photo and video access inside.
The Republican former president is expected to be joined in court by attorneys Todd Blanche and Chris Kise. But Mr Trump will continue to meet with other Florida lawyers this week after two of his attorneys quit last week.
Mr Trump, who has repeatedly denied wrongdoing, is expected to return to his golf resort in Bedminster, New Jersey, where he will make remarks to the media.