A stony-faced Donald Trump has pleaded not guilty to 34 criminal felonies as he was formally arrested on Wednesday morning (AEDT) while surrendering to a New York court in a historic appearance.

The former US president was not handcuffed as he silently entered the courthouse in Manhattan and sat alongside his defence team as the charges were officially unsealed.

“Not guilty,” said Mr Trump when asked how he pleaded.

The allegations were 34 counts of falsifying business records to “conceal a crime” before the 2016 presidential election.

Mr Trump, 76, did not speak to the media or release a public statement as he attended the court to surrender to authorities.

He left Trump Tower early Wednesday (AEDT) and gave the cameras a fist pump before he was escorted to the courthouse through New York streets by the Secret Service.

From his motorcade, Mr Trump posted on social media: “Heading to Lower Manhattan, the Courthouse. Seems so SURREAL — WOW, they are going to ARREST ME. Can’t believe this is happening in America.”

Mr Trump was fingerprinted but no mugshot photo was taken, according to a Twitter post by a New York Times reporter.

Photos inside the courthouse on the 15th floor showed Mr Trump walking down a hallway as he was led by police and Secret Service detail.

He remained silent as he entered the courtroom and took a seat alongside his lawyers.

Media were banned from live broadcasting the historic appearance but a small pool of photographers were permitted to take still images.

Mr Trump was in the courtroom for about one hour before he was released on bail.

He left the building, again not making any comment to media or his supporters gathered outside, and was whisked away through lower Manhattan in a motorcade.

He then boarded his private jet and was expected to return to Florida and deliver remarks from his Mar-a-Lago resort on Tuesday night (local time), his office said.

The first sitting or former US president to face criminal charges, Mr Trump was indicted by a Manhattan grand jury last week in a case stemming from a 2016 hush-money payment to porn star Stormy Daniels.

Fake business records

After Mr Trump’s appearance, the prosecutor, New York District Attorney Alvin Bragg, commented on the case for the first time.

Mr Bragg revealed the charges related to Mr Trump repeatedly making false statements on New York business records “to cover up other crimes related to the 2016 presidential election”.

He said Mr Trump claimed he had been making payments to lawyer Michael Cohen for legal services, but “this was not true”.

Mr Cohen is Mr Trump’s former lawyer who has admitted paying Ms Daniels $US130,000 ($190,000) in exchange for her silence before the 2016 election.

“These are felony crimes in New York State, no matter who you are,” said Mr Bragg.

“We can not and will not normalise serious criminal conduct.”

Mr Bragg said Mr Trump and others made payments to people who claimed to have negative information about him.

One of the people paid was allegedly Ms Daniels.

While falsifying business records in New York on its own is a misdemeanour punishable by no more than one year in prison, it is elevated to a felony punishable by up to four years in prison when done to advance or conceal another crime.

Together Mr Trump’s charges carry a maximum sentence of more than 100 years in prison, but an actual prison sentence if he is convicted at a trial would almost certainly be far less than that.

Donald Trump walks towards the courtroom inside New York Criminal Court. Photo: AAP

Mr Trump, the front-runner for the 2024 Republican presidential nomination, is the first sitting or former president to face criminal charges.

Being indicted or even convicted does not legally prevent Mr Trump from running for president.

In November he announced a bid to regain the presidency in 2024 in a bid to deny Democratic President Joe Biden, who beat him in 2020, a second term in the White House.

Outside the courthouse Trump supporters and detractors were separated by barricades set up by police to try to keep order, though there were some confrontations.

“Let’s keep it civil, folks,” a police officer told them.

Hundreds of Trump supporters, at a park across from the Manhattan courthouse, cheered and blew whistles, outnumbering his detractors.

The Trump critics held signs, including one of Mr Trump dressed in a striped jail uniform behind bars and another that read, “Lock him up.”

Any trial is at least more than a year away, legal experts said.

Hush money

The Manhattan grand jury that indicted Mr Trump heard evidence about the $US130,000 payment to Ms Daniels in the waning days of the 2016 presidential campaign.

Ms Daniels has said she was paid to keep silent about a sexual encounter with Mr Trump at a Lake Tahoe hotel in 2006.

Mr Trump denies a sexual relationship but has acknowledged reimbursing his former personal lawyer Michael Cohen for the payment.

Mr Trump faces a separate criminal probe by a Democratic local prosecutor in Georgia into whether he unlawfully tried to overturn his 2020 election defeat in the state.

He also faces two US Justice Department investigations led by a special counsel into efforts to overturn the 2020 election results and his handling of classified documents after leaving office.

-with AAP