The Army charged the 23-year-old private in May while he was assigned as an intelligence analyst with a combat brigade in Iraq. Since July, he has been held in solitary confinement in the brig atMarine Corps Base Quantico in Virginia.

"What's happening right now, they are convening a 706 board, which is a board to determine his mental fitness, which was requested by the defense," Col. Manning said. "Because of the nature of the charges, that board is being screened. Once that board meets and determines Pfc. Manning's mental fitness, then they will continue to move forward with the Uniform Code of Military Justice process. That's the first thing that needs to happen, this 706 board. … I don't have a timeline on that."

The 706 refers to a section of the Manual for Courts-Martial. The board must answer two questions: Was the accused suffering from a mental disease that made him unable to appreciate the wrongfulness of the conduct? Is the accused mentally competent to stand trial?

Col. Manning is a spokesman for the U.S. Army Military District of Washington, whose commander, Maj. Gen. Karl R. Horst, is overseeing the case against Pfc. Manning.

David E. Coombs, an Army Reserve officer who is Pfc. Manning's defense attorney, has chronicled his client's treatment at Quantico on his law firm's website. The treatment includes denial of sheets and a pillow and constant observation by guards.

Col. Manning said Pfc. Manning is not on a suicide watch. "The classification is 'maximum custody detainee under constant observation,'" he said. "But he has not been on suicide watch."

Pfc. Manning's supporters have asserted that his treatment amounts to torture and want the United Nations to investigate. The Army says he is being treated humanely.

In a Dec. 18 posting, Mr. Coombs described his client's living conditions: "His cell is approximately six feet wide and twelve feet in length. The cell has a bed, a drinking fountain, and a toilet. The guards at the confinement facility are professional. At no time have they tried to bully, harass, or embarrass PFC Manning. Given the nature of their job, however, they do not engage in conversation with PFC Manning.

"At 5:00 a.m. he is woken up (on weekends, he is allowed to sleep until 7:00 a.m.). Under the rules for the confinement facility, he is not allowed to sleep at anytime between 5:00 a.m. and 8:00 p.m. If he attempts to sleep during those hours, he will be made to sit up or stand by the guards."

Mr. Coombs said the prisoner gets one hour of exercise a day, which consists of walking in a room. He is allowed a 15- to 20-minute shower each night.

The lawyer said he has raised Pfc. Manning's strict confinement conditions with the chain of command. "Our efforts, unfortunately, have not resulted any in positive results," he said.

The law office also released a "holiday statement" from Pfc. Manning:

"I greatly appreciate everyone's support and well wishes during this time. I am also thankful for everything that has been done to aid in my defense. I ask that everyone takes the time to remember those who are separated from their loved ones at this time due to deployment and important missions. Specifically, I am thinking of those that I deployed with and have not seen for the last seven months, and of the staff here at the Quantico Confinement Facility who will be spending their Christmas without their family."

The Army's official charging document accuses Pfc. Manning of accessing the military's vast Secret Internet Protocol Router Network and downloading more than 150,000 State Department cables.

WikiLeaks, the self-described whistleblower network, is releasing more than 250,000 secret cables, but has not acknowledged Pfc. Manning as its source.

WikiLeaks founder Julian Assange has called Pfc. Manning a "political prisoner." Various press reports have quoted Pfc. Manning as telling a hacker that he downloaded the files while pretending to listen to music at a computer station.