Eduardo Balarezo told reporters on Tuesday that he is seeking a psychological evaluation for Guzman before he goes to trial later this year in US federal court in New York City.

The lawyer spoke outside court following a pre-trial hearing.

Guzman has repeatedly complained about being held in solitary since he was sent to the United States in 2017 to face charges that his Sinaloa cartel laundered billions of dollars and oversaw a ruthless campaign of murders and kidnappings.

He claims because of the conditions, he has suffered headaches, memory-loss and other illnesses.

Prosecutors say the tight security is needed because Guzman's history of jail breaks in Mexico.

US District Judge Brian Cogan said he planned to call between 800 and 1000 potential jurors in a sign of how difficult it will be to successfully try the 61-year-old on trafficking and conspiracy charges.

The unusual size of the pool reflects the expected difficulty of choosing jurors to weigh the fate of Guzman. Typical cases involve much smaller jury pools.

Prosecutors have said jurors might fear for their safety, and Cogan ordered in February that their identities should be kept secret.

Australian Associated Press