GUANTANAMO BAY NAVAL BASE, Cuba — An Australian terror suspect pleaded guilty yesterday to a war-crime charge of providing material support to terrorism.

David Hicks was the first detainee to face prosecution under revised military tribunals set up after the Supreme Court found the Pentagon’s previous system for trying Guantanamo prisoners unconstitutional. He is accused of fighting alongside Al Qaeda in Afghanistan.

Hicks entered the plea before a military judge in a courtroom on this U.S. naval base. Hicks had deferred entering a plea during his arraignment earlier in the day, but the presiding officer, Marine Colonel Ralph Kohlmann, convened another session after lawyers told him Hicks would enter a plea. Colonel Kohlmann ordered attorneys to attend another session today to sort out details of the plea.

Hicks’s Pentagon-appointed attorney, Marine Corps Major Michael Mori, told the judge that his client would plead guilty to one of two counts of providing material support for terrorism and innocent to the other. Hicks, standing by Major Mori’s side, told the judge that was his wish.

Defense attorneys said Hicks did not expect a fair trial at Guantanamo and was considering a plea deal to end his five-year imprisonment. American officials have said he would be able to serve any sentence in Australia.

Terry Hicks, who had an emotional reunion with his son before the arraignment yesterday, had boarded a plane to leave Guantanamo when he was told another session would be held, according to U.S. military officials, and did not appear in the courtroom for the second session.

In the first session yesterday, Hicks asked for more lawyers to help defend him but the presiding military officer instead ordered two civilian attorneys to leave the defense table, leaving the defendant with only one attorney.

The heavyset 31-year-old, wearing a khaki prison jumpsuit, had told the court he was satisfied with his defense team but wanted more lawyers and paralegals “to get equality with the prosecution.”

Colonel Kohlmann instead said two civilian lawyers, including a Defense Department attorney, were not authorized to represent Hicks. He ordered them to leave the defense table when Hicks said he would not settle for them being designated consultants.

One of the lawyers, Joshua Dratel, said he refused to sign an agreement to abide by tribunal rules because he was concerned the provisions did not allow him to meet with his client in private.

“I’m shocked because I just lost another lawyer,” Hicks said after Mr. Dratel’s departure, drawing a scolding from the judge for interrupting as he explained the reasoning for removing the lawyers.

Major Mori challenged Colonel Kohlmann’s partiality, arguing that his participation in the previous round of military trials that the Supreme Court last year found to be illegal created the appearance of bias.