Donald Trump faces twin legal crises on Monday in New York, where he could see the possible seizure of his storied properties over a massive fine as he separately fights to delay a criminal trial even further.

The 77-year-old real estate magnate, who has once again clinched the Republican nomination despite facing a raft of legal charges, has already been hit by heavy fines in two civil cases.

In his case over business fraud, his lawyers on Monday must either prove that he can guarantee payment of the $454 million fine or face the possible seizure of some of his assets.

Judge Arthur Engoron imposed that fine after finding Trump and his two adult sons guilty in a non-jury trial.

If Trump is unable to provide the needed bond -- and his lawyers have said they have tried in vain to secure one -- then "obviously his image would change dramatically, I would think, for many people, because he has said that he's a billionaire and very successful," Andrew Weissmann, a former federal prosecutor and author of the book "The Trump Indictments," told AFP.

"And if he cannot post a bond in any amount, that obviously is a huge problem."

Separately, a criminal court in Manhattan convenes at 9:30 am (1330 GMT) to set a new date in his historic trial over payments to porn star Stormy Daniels.

- 'Prospect of humiliation' -

The former president took to his Truth Social platform Saturday to again blast Judge Engoron and New York Attorney General Letitia James in no uncertain terms.

In one all-caps message he denounced the judge as "GROSSLY INCOMPETENT AND CORRUPT," and in another he said James "GOES AFTER TRUMP FOR DOING ABSOLUTELY NOTHING WRONG!"

Trump regularly rails against a judicial system he says is "fixed" against him. He has said James -- who is Black -- is "racist," and accused Engoron of being a "crooked judge" controlled by Democrats.

Despite Trump's supposed inability to secure a bond, he bragged online on Friday that due to "hard work, talent, and luck" he had almost $500 million in cash, which he said he had planned to spend on his election campaign against President Joe Biden.

The judge, he said, "knew this (and) wanted to take it away from me."

Trump got some positive financial news on Friday, when it was announced that Truth Social would finally go public through a merger, a transaction that could net him billions of dollars.

He cannot tap into the funds for six months, but it potentially could help him secure a bond.

If he fails to do so, Carl Tobias of the University of Richmond law school said Trump "confronts the prospect of humiliation and serious financial harm."

James could order a freeze on his bank accounts, or move to seize some of his New York properties.

Trump might "even declare bankruptcy," Tobias said.

- Seeking more delays -

His lawyers have pursued every possible avenue to delay his many trials -- if possible until after the November 5 presidential elections.

The trial involving Stormy Daniels, whose real name is Stephanie Clifford, was originally set to begin Monday, but has been pushed back at least a month. He stands accused of illegally using campaign funds to secure her silence about an alleged affair.

The former president, who has denied having the affair, potentially could face a prison sentence of up to four years if convicted.

His legal team is requesting a delay of at least three months to allow them time to study thousands of pages of evidence belatedly provided by prosecutors.

They also want the trial to wait until the US Supreme Court rules on his claim to have absolute immunity for actions taken while he was president.