A court in the US state of Florida has indefinitely postponed a trial of former President Donald Trump over his handling of classified government documents.

Trump is accused of illegally keeping highly classified documents, including those pertaining to nuclear arms and military capabilities, at his home in Florida after he left office, in violation of the Espionage Act.

A federal court in Florida said on Tuesday it would be imprudent to go through with the trial until numerous procedures needed to handle classified information as evidence have been completed. The trial was scheduled for May 20 and a new date has not been set.

Trump, who is seeking to reclaim the presidency, is facing four criminal cases.

But three of the trials, including the classified documents case, have been postponed.

US media reports say it is highly likely that only the hush money case will be tried before the November election.

The decision by the Florida court could be of advantage to Trump, who wants to avoid any negative impact from these cases on his campaign.