Former US president Donald Trump arrived in Miami, Florida, on Monday, a day before his arraignment on 37 felony charges over his retention of classified documents and refusal to return them to federal authorities.
His arraignment at a courthouse on Tuesday afternoon will make him the first former or current president to face federal charges.
The Justice Department on Friday unsealed an indictment that revealed Mr Trump is being accused of wilful possession of national security secrets after his presidency ended in 2021, conspiracy to commit obstruction of justice and making false statements.
There are also charges connected to the Espionage Act, which includes potential prison time if he is convicted.
It is expected that Mr Trump will surrender to authorities ahead of his 3pm court hearing, when his charges will be formally read to him and he can enter an initial plea. He has claimed he is innocent of all charges.
Mr Trump called for protests by supporters and Miami police said they were prepared.
“We’re taking this event extremely seriously. We know that there is a potential of things taking a turn for the worst, but that’s not the Miami way,” Miami Police Chief Manny Morales said in a press briefing.
The leading Republican candidate in the 2024 presidential election published several posts on his Truth Social platform calling the indictment election interference. President Joe Biden does not have the power to indict individuals and special counsel Jack Smith has independence in his oversight of Trump investigations.
Mr Trump said that he would appoint a special counsel to investigate Mr Biden if he were elected to a second term as president.
A poll by ABC/Ipsos found that 61 per cent of Americans think the charges against Mr Trump are serious – including 91 per cent of Democrats and 38 per cent of Republicans.
People were, however, split on what should happen next: 48 per cent said he should be charged, and 46 per cent say he should also suspend his presidential campaign. Forty-seven per cent of those polled believe the charges are politically motivated.
Mr Trump plans to return to his Bedminster club in New Jersey after the arraignment for a Tuesday evening speech and fundraiser.