“If this Partisan Hack wants to put me in the ‘clink’ for speaking the open and obvious TRUTH, I will gladly become a Modern Day Nelson Mandela – It will be my GREAT HONOR,” Trump posted on Saturday on his Truth Social platform.

Trump was referring to Justice Juan Merchan, who will preside over his trial in New York state court in Manhattan on criminal charges of covering up a $US130,000 ($A197,542) payment before the 2016 election to porn star Stormy Daniels to buy her silence about an alleged sexual encounter.

The trial begins on April 15.

The Republican, who is challenging Democratic President Joe Biden in the November 5 US presidential election, has pleaded not guilty to 34 counts of falsifying business records and denies an encounter with Daniels, whose real name is Stephanie Clifford.

Merchan on April 1 expanded an existing gag order that had barred Trump from publicly commenting about witnesses and court staff to make clear it also applies to family members. He did so after Trump disparaged Merchan’s daughter.

The looming hush-money trial is one of four criminal cases Trump is confronting ahead of the US election. It could be the only one to reach trial before the election. He has pleaded not guilty to all and called them politically-motivated.

– AAP