Hernandez was extradited to the United States on drug charges in 2022, accused of orchestrating the smuggling of 500 tons of cocaine in exchange for millions of dollars in bribes.
The trial delay occurred because US prosecutors were unable to complete the redaction of classified information, which was supposed to have already been handed over to the defense, lawyer Raymond Colon said.
Hernandez, 55, has maintained his innocence.
As president, he worked closely with the administration of former US president Donald Trump and received praise from Washington for his government’s efforts in drug seizures and combating organised crime.
If found guilty of the three charges against him — conspiracy to traffic drugs and two counts of weapons trafficking and possession — Hernandez could face life imprisonment.
A conviction would place him among other former Latin American leaders who have been tried and found guilty in the United States, including Panama’s Manuel Noriega in 1992 and Guatemala’s Alfonso Portillo in 2014.