FORT BRAGG, N.C. — An Army judge is considering how classified information should be handled in the case against Sergeant Bowe Bergdahl, who walked off an outpost in Afghanistan in 2009.

Bergdahl’s attorneys argued at a hearing Tuesday for wider leeway in their ability to gather and use the classified information in his case. He faces charges of desertion and misbehavior before the enemy, a relatively rare charge that carries a punishment of up to life in prison.

Bergdahl, 29, walked into the courtroom briskly wearing a dress blue uniform and sat up straight and quietly for the 2½ hour hearing. He spoke only to answer several ‘‘yes’’ or ‘‘no’’ questions from the judge, Colonel Jeffery Nance.

Defense attorney Lieutenant Colonel Frank Rosenblatt argued that the prosecution wants to apply military rules on classified information in a way that would hinder the defense. Rosenblatt cited an example in which he said prosecutors put restrictions on what a potential witness could answer during an interview, hindering their evidence-gathering.

The judge said ‘‘the big issue still left to be determined is whether the defense should have to go through trial counsel’’ or other military authorities to get access to classified information.

Bergdahl, who was held by the Taliban for five years after he walked off a base, was arraigned in December. He has yet to enter a plea or decide whether he wants a trial before a jury or just the judge.