NEW YORK -- Former US President Donald Trump on Monday appeared in a criminal court in Manhattan, New York City, in the hush money case, making him the first former US president to stand a criminal trial.

Trump arrived at the court in Lower Manhattan around 9 am with a heavy presence of security guards, press representatives as well as activists from different political camps.

Trump descended from his motorcade and talked to the press briefly before entering the courtroom.

"The trial is a political persecution... It's an assault on America... it's a country that's failing," said Trump.

The case should never have been brought, said Trump, who also complained about the gag order imposed on him.

Trump's lawyers made at least three tries in the previous week in order to delay the trial but the requests were denied by judges.

Facing 34 felony counts on falsifying business records in a bid to hide hush money payment of 130,000 US dollars to porn star Stormy Daniels in 2016, Trump is expected to be present at the court very often as the trial goes on.

The trial is expected to last six to eight weeks as jury selection kicked off on Monday, according to a release by New York State Unified Court System.

Carrying flags and banners, a number of Trump supporters and critics went to Collect Pond Park in front of the court building, and they even traded barbs.

"Our legal system is corrupt, and I'm here to stand with Trump because he's much more honorable than our court system," said Steve Merczynski, a New Yorker, who supports Trump by marketing themed hammocks and hammock chairs.

Merczynski said the US judicial system is partisan and the problem makes people don't trust the system, noting that he expected Trump to be found guilty as the vast majority of the jury in New York City are Democrats.

"The justice system is on trial... I think if Trump is found guilty, it shows we don't have a fair system here, because this case should not have been brought. If he's found not guilty, or if there's a hung jury, I have faith in the system that at least some people know of the baloney that this case is a mistake," he said.

For Marc Leavitt, nevertheless, "this is a beautiful day for a trial and for the rule of law."

"I believe strongly in democracy. No man or woman is above the law. Everyone has the right to be proven innocent or guilty," said Leavitt, who wore a placard criticising Trump.

A group of protesters marched by the court building in the morning and carried a big banner which read "No one is above the law."

Leavitt said he believes Trump would get a fair trial in the hush money case and the Republican Party could have chosen a much more worthy candidate in the upcoming presidential election, but he also believes that Trump is guilty of subverting democracy and a "former embarrassment in chief and a scourge on our democracy."

Trump, the Republican Party's presumptive presidential nominee in the 2024 US general election, is facing four criminal indictments, and a conviction in one criminal trial would dampen his presidential campaign, analysts say.