Former US President Donald Trump, the only ex-president to face criminal charges, has told his supporters “our country is going to hell”.

Following his appearance before a Manhattan court where he pleaded not guilty to 34 felony counts of falsifying business records, Trump flew back to his Mar-a-Lago resort in Florida where he addressed a crowd of 500 supporters.

Flanked by American flags, he delivered a campaign-style speech to the cheering crowd.

In a rambling 25-minute-long speech in which he took aim at various prosecutors investigating him on multiple fronts, he said it was “the most embarrassing time in our country’s history”.

He said the “fake case” relating to hush money payments to suppress accounts of his alleged extramarital affairs becoming public, was brought to “interfere in the 2024 election and should be immediately dropped”.

He lashed out at New York prosecutor Alvin Bragg for bringing criminal charges against him saying he was out to get him “before he knew anything about me”.

"I never thought anything like this could happen in America," he told his supporters.

"The only crime that I've committed has been to fearlessly defend our nation against those who seek to destroy it."

He said he spent time with a “local failed district attorney” today who charged a former president of the US for the first time in history.

"Every single pundit and legal analyst said there is no case. Virtually every one," he said, adding the case should never have been brought.

Earlier at the court hearing in New York, Judge Juan Merchan warned Trump to refrain from rhetoric that could inflame or cause civil unrest.

Hours later, the former president described Merchan as “a Trump-hating judge”.

A defiant Trump, referring to the indictment, said "this is a persecution not an investigation" but "our heads are held very high".

Trump lawyer Todd Blanche told reporters that it was a “sad day for the country.” “You don’t expect this to happen to somebody who was president of the United States,” he said.

Trump faces a separate criminal probe by a county 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 attempts to overturn the 2020 election results and his handling of classified documents after leaving office.

"They can't beat us at the ballot box so they try to beat us through the law," Trump said.

He also referred to the investigation into his handling of classified documents that were taken to Mar-a-Lago when he moved out of the White House in early 2021.

The documents case is being pursued by a "lunatic special counsel", Trump said, referring to prosecutor Jack Smith

The various legal predicaments are entangling Trump has he makes another run for the Republican presidential nomination in 2024.

Earlier in a social media post from his plane on his flight home from New York, Trump said the court hearing "was shocking to many in that they had no ‘surprises,’ and therefore, no case. Virtually every legal pundit has said that there is no case here. There was nothing done illegally!”

Speaking after the court hearing, Bragg says his office’s historic case against the former seeks to “ensure that everyone stands equal before the law.”

“No amount of money and no amount of power changes that enduring American principle,” he said.

Democratic Representative Jamaal Bowman of New York has said that former president Donald Trump’s arraignment is just “one step towards accountability.”

The progressive Democratic member of the Squad - which includes Representatives Cori Bush of Missouri, Rashida Tlaib of Michigan, Ayanna Pressley of Massachusetts, Ilhan Omar of Minnesota and fellow New Yorker Alexandria Ocasio-Cortez - said shortly before the former president’s arraignment.