Donald Trump is expected to be arraigned as soon as Tuesday on more than 30 charges after his historic indictment was revealed.

Mr Trump was believed to still be at his Florida home on Thursday (local time) as crowds gathered outside to show their support after he became the first current or former US president to face criminal charges.

His defence lawyer said he would be arraigned in New York on Tuesday. CNN is also reporting that multiple sources say the former president will appear in court, where the charges against him will be read out.

Before that, he will have to hand himself in to Manhattan authorities to be finger-printed and have a mugshot taken.

A spokesperson for Manhattan District Attorney Alvin Bragg said the office had contacted Mr Trump’s lawyer to “coordinate his surrender” for arraignment on “a Supreme Court indictment, which remains under seal.”

“Guidance will be provided when the arraignment date is selected,” the spokesperson said.

Thursday’s much anticipated announcement came after a long-running probe into hush money paid to porn star Stormy Daniels.

The charges, arising Mr Bragg’s investigation, could reshape the 2024 US presidential race. Mr Trump previously said he would continue campaigning for the Republican Party’s nomination if charged with a crime.

In a statement on Thursday, he said he was “completely innocent”.

“This is Political Persecution and Election Interference at the highest level in history,” he said, providing no evidence.

He was also already using the indictment as a fundraiser. Within hours of it emerging, he emailed donors asking for money “to defend our movement from the never-ending witch hunts”.

He claimed donations would have a “1500 per cent impact” – although he didn’t explain what that meant.

There are multiple reports that Mr Trump faces more than 30 counts related to business fraud in the indictment from the Manhattan grand jury.

Mr Trump’s lawyers Susan Necheles and Joseph Tacopina said they would “vigorously fight” the charges.

“President Trump has been indicted. He did not commit any crime. We will vigorously fight this this political prosecution in Court,” they said in a joint statement.

Ms Necheles said she did not know when Mr Trump would surrender.

Mr Bragg’s office did not immediately respond to requests for comment.

The Manhattan investigation is one of several legal challenges facing Mr Trump, and the charges could hurt his presidential comeback attempt. Some 44 per cent of Republicans said he should drop out of the race if he was indicted, according to a Reuters/Ipsos poll released last week.

The White House declined to comment.

Mr Bragg’s office last year won the criminal conviction of the businessman-turned-politician’s real estate company.

The grand jury convened by Mr Bragg in January began hearing evidence about Mr Trump’s role in the payment to Ms Daniels days before the 2016 presidential election that he ended up winning. Ms Daniels, a well-known adult film actress and director whose real name is Stephanie Clifford, has said she received the money in exchange for keeping silent about a sexual encounter she had with Mr Trump in 2006.

She said the encounter was at a Lake Tahoe hotel in 2006, the year after Mr Trump married his current wife Melania and more than a decade before the businessman-turned-politician became president.

Tweet from @ManhattanDA

Mr Trump also faces two criminal investigations by a special counsel appointed by US Attorney General Merrick Garland and one by a local prosecutor in Georgia.

He leads his early rivals for the Republican nomination for the 2024 presidential race, with 44 per cent support in a March Reuters/Ipsos poll, compared with 30 per cent support for his nearest rival, Florida Governor Ron DeSantis, who has yet to announce his candidacy. President Joe Biden is expected to seek re-election.

Mr DeSantis weighed into the Trump indictment on Thursday, calling it “un-American” and saying Florida would not assist in any extradition request.

“The weaponisation of the legal system to advance a political agenda turns the rule of law on its head. It is un-American,” he tweeted.

Florida law allows the governor to intervene in contested extradition matters. Mr Trump’s lawyers have previously indicated they have no plans on fighting his extradition to New York.

Other senior Republicans also rallied around Mr Trump. His vice-president, Mike Pence, criticised the charges.

“I think the unprecedented indictment of a former president of the United States on a campaign finance issue is an outrage,” he told CNN.

“This will only further serve to divide our country.”

Mr Trump falsely claims that his 2020 re-election loss to Mr Biden was the result of widespread voting fraud.

On March 18, he urged his supporters to protest to “take our nation back” ahead of an expected indictment, recalling his exhortations ahead of the January 6, 2021, attack on the US Capitol.

In the case that led to the conviction of the Trump Organisation on tax fraud charges, Mr Bragg declined to charge Mr Trump himself with financial crimes related to his business practices, prompting two prosecutors who worked on the probe to resign.

Among Mr Trump’s ongoing legal woes are a criminal investigation led by Fani Willis, the Democratic district attorney in Georgia’s Fulton County, into whether he unlawfully tried to overturn his 2020 election defeat in that state.

Special counsel Jack Smith is separately investigating Mr Trump’s handling of classified government documents after leaving office and his efforts to overturn the results of the 2020 election.

-with AAP