Former US President Donald Trump has been consulting lawyers at Trump Tower in New York City as he prepares to face history-making criminal charges.
He has been under investigation over hush money paid just before the 2016 election to a porn star who says they had sex. He denies wrongdoing.
Extra security measures are in place with the authorities expecting protests outside the Manhattan court on Tuesday.
Mr Trump, 76, is the first ex-US president to face a criminal case.
“WITCH HUNT,” the Republican wrote on his Truth Social platform shortly before travelling from his home in Florida to New York on Monday – a journey which drew blanket coverage across the US news channels.
On Tuesday morning, dozens of police and court officers, as well as Secret Service agents, are expected to escort Mr Trump through the streets of New York to the Lower Manhattan court complex.
The charges he faces will be disclosed in full at the hearing, which is scheduled for about 14:15 local time (19:15 BST). His lawyers have already said he will plead not guilty.
The former president is expected first to surrender at the office of Manhattan district attorney Alvin Bragg.
Once Mr Trump is fingerprinted and processed by officials, he is considered under arrest and in custody. He will then be arraigned in court – meaning the charges will be read out and he will plead.
Mr Trump has been under investigation over a $130,000 (£105,000) wire transfer by his former attorney, Michael Cohen, to adult film star Stormy Daniels before the 2016 presidential election.
Mr Trump has denied a sexual encounter with Ms Daniels.
Hush money agreements are not illegal, but the Manhattan prosecutor has been investigating whether business records were falsified in relation to the payment.
Mr Trump faces at least one felony charge in the case, according to US media. Other reports suggest there are about 30 counts in his indictment.
Media outlets lobbied Judge Juan Merchan to allow cameras inside the court, a motion that was opposed by Mr Trump’s legal team because they said it would “create a circus-like atmosphere at the arraignment”.
But on Monday night, Judge Merchan ruled that some press photographers will be allowed to take pictures for several minutes before the arraignment formally starts.
The former president is expected to be released on bail and to return to his Florida home Mar-a-Lago on Tuesday evening, where he plans to deliver remarks at 20:15 local time.
His trip on Monday lunchtime from Palm Beach to Manhattan was closely watched by millions.
Live trackers followed his plane – painted in red, white and blue with “Trump” in big letters on the side – throughout the nearly four-hour flight from West Palm Beach to LaGuardia Airport in Queens.
Anticipating his arrival, the intersection around Trump Tower – the former president’s Manhattan residence – was thronged with New Yorkers and tourists alike.
Dozens of media crews had set up camp on every available corner while at least five news helicopters hovered high over Fifth Avenue.
Mr Trump waved at media and the crowd before walking in to the skyscraper under tight security, just after 16:15 local time (20:15 GMT).
He is understood to have spent Monday evening at Trump Tower consulting with legal advisers, a team that grew with the addition of Todd Blanche, a white-collar criminal defence lawyer and ex-federal prosecutor who previously represented onetime Trump campaign chairman Paul Manafort.
Mr Trump’s 2024 White House campaign has raised over $8m since news of the charges against him broke last week, according to his team.
At a news conference on Monday, New York City Mayor Eric Adams warned any potential “rabble-rousers” to “control yourselves”.
Georgia congresswoman Marjorie Taylor Greene plans to hold a pro-Trump rally near the court on Tuesday.
Unlike the days preceding the Capitol riot in 2021 by Trump supporters, New York officials say they have not seen any influx of protesters to the city in recent days.
President Joe Biden, at an event in the state of Minnesota on Monday, told reporters he had no concerns about unrest in New York, saying: “I have faith in the New York Police Department.”