Former U.S. President Donald Trump came to New York on Monday to surrender to criminal charges, as he attempts to get reelected in next year's elections.

The 76-year-old Republican, the first U.S. president ever to be criminally indicted, will be formally charged Tuesday over hush money paid to a porn star during the 2016 election campaign.

Trump touched down at LaGuardia Airport after a two-and-a-half-hour flight from Florida, on board a private Boeing 757 emblazoned with his name on the fuselage – a historic journey given wall-to-wall live coverage on U.S. television.

Trump was due to head to Trump Tower, where he was to spend the night before heading Tuesday afternoon to the Manhattan courthouse where he will try to use his appearance before a judge to rouse support for his 2024 White House bid.

"THEY'RE NOT COMING AFTER ME, THEY'RE COMING AFTER YOU – I'M JUST STANDING IN THEIR WAY!" Trump wrote on his social media platform Truth Social, one of a dozen posts he made en route from his Florida mansion to New York.

Police in the city were on high alert with security cordons and Secret Service agents outside Trump Tower on Fifth Avenue and the court in Lower Manhattan.

Mayor Eric Adams warned that anyone protesting violently during Trump's historic arraignment will be "arrested and held accountable, no matter who you are."

"While there may be some rabble rousers thinking about coming to our city tomorrow our message is clear, is simple: 'control yourselves,'" the mayor told a news conference, adding that there were no specific, credible threats.

As part of his arraignment, Trump will undergo the standard booking procedure of being fingerprinted and photographed, likely to result in one of the most famous mugshots of the modern era.

There is no roadmap for a former president's surrender to court authorities, and it remains to be seen whether the famously unpredictable Trump will follow the script, or find a way to upend events.

"It's all up in the air," Trump lawyer Joe Tacopina said on CNN Sunday.

But a "perp walk" – in which a defendant is escorted in handcuffs past media cameras – is unlikely for an ex-president under U.S. Secret Service protection, Tacopina said.

Trump is girding for battle and will plead not guilty, Tacopina added.

A grand jury indicted Trump last week in the case brought by Manhattan District Attorney Alvin Bragg, an elected Democrat.

The specific charges will be revealed during Tuesday's hearing. They revolve around the investigation of $130,000 paid to pornographic actress Stormy Daniels just days before Trump's election win.

Trump's former lawyer and aide Michael Cohen, who has since turned against his ex-boss, says he arranged the payment to Daniels in exchange for her silence about a tryst she says she had with Trump in 2006.

Trump, whose third wife Melania had recently given birth at the time, denies the affair.

Legal experts have suggested that if not properly accounted for, the payment could result in misdemeanor charges for falsifying business records that could be raised to felonies if it was intended to cover up a campaign finance violation.

Republicans unite?

Trump is facing several criminal investigations at the state and federal level over possible wrongdoing that threaten his new run at the White House.

They include his efforts to overturn his 2020 election loss in the state of Georgia, his handling of classified documents, and his possible involvement in the Jan. 6 rioting.

Republicans have largely rallied around Trump, including his rival in the party's presidential primary, Florida Gov. Ron DeSantis, who called the indictment "un-American."

But some Republicans bristled at the prospect of a twice-impeached president facing multiple legal probes seeking the party's nomination.

President Joe Biden, mindful that anything he might say could fuel Trump's complaints of a politically "weaponized" judicial system, is one of the few Democrats maintaining silence over the indictment of his political rival.

Some observers believe the indictment bodes ill for Trump's 2024 chances, while others say it could boost his support.

"I think the Democratic Party is doing this just for election interference," 71-year-old Trump supporter Vito Dichiara told Agence France-Presse (AFP) outside Trump Tower.

New Yorker Lea Sturley said: "I think it's important that we understand that this is not about sides. It's about justice."

A CNN poll Monday found that 94% of Democrats surveyed approved of the decision to indict Trump while 79% of Republicans disapproved.