FORT BRAGG, N.C. -- A U.S. Army judge is considering how to handle thousands of documents, many of them classified, that will be part of the case against a soldier who walked off an outpost in Afghanistan.

Sgt. Bowe Bergdahl appeared on Tuesday before an Army judge for the pretrial hearing at Fort Bragg in North Carolina. He faces charges of desertion and misbehaviour before the enemy.

The judge is preparing an order that will shape how the defence can use classified information to prepare its case.

Prosecutor Capt. Michael Petrusic estimated the discovery process could involve more than 300,000 pages.

Defence attorney Lt. Col. Frank Rosenblatt argued the prosecution's desired approach would place obstacles in front of Bergdahl's lawyers.

Bergdahl's military trial is expected to start this summer.