An attorney defending a Canadian teenager accused of killing a U.S. soldier in Afghanistan called for proceedings to be halted during a hearing punctuated by clashes over a lack of established rules for the military trials.

Army Capt. John Merriam, an attorney for 19-year-old Omar Khadr, asked the judge to suspend proceedings "until the government gets the rules together."

The judge, Marine Col. Robert S. Chester, said he would rule on the request after reading relevant material delivered by the defense.

Wednesday's hearing at the isolated U.S. military base at Guantanamo Bay, Cuba, was rattled by shouting and table-banging as Chester and another of Khadr's defense attorneys clashed over the lack of rules for the first military tribunals since the World War II era.

Early in the session, Khadr said he was boycotting the proceedings because he has been kept in solitary confinement since March 30. Chester berated the defense attorney, Marine Lt. Col. Colby Vokey, for not having warned him earlier of the situation.

As the voices grew louder, Vokey banged his hand on a varnished wood table and shouted that he hadn't had an opportunity to alert the judge.

"Every time we come down here there is an incredible burden just to do my job," Vokey shouted. Chester then called a recess.

Chester said the issue of Khadr's solitary confinement would be addressed later in the week.

Khadr, who has a sparse beard and was dressed in a blue checked shirt, khaki pants and Reebok sneakers, remained in the courtroom as the pretrial hearing continued.

Late Wednesday, Navy Cmdr. Robert Durand issued a statement saying no detainees at Guantanamo Bay are put in solitary confinement but adding that detainees "in a pretrial status are separated" from the general population. Khadr was moved to a cell alone in a higher-security area for his own protection but still can see and talk to other inmates on his tier, Durand told The Associated Press.

Vokey and the judge also clashed about trial procedures to bring in a Canadian consulting attorney requested by the Toronto-born Khadr, who was 15 when he was captured in Afghanistan.

Chester asked Vokey if he had filed a brief requesting a Canadian attorney as a consultant. Only lawyers who are U.S. citizens are permitted to directly participate. The judge then told Vokey that even if a brief was filed, he didn't know if he had the authority to allow a Canadian attorney into the courtroom.

"There are no rules here," Vokey retorted. "It seems kind of crazy, if the presiding officer doesn't have the authority to act on it, to go to the presiding officer."

In a separate hearing Tuesday, Chester refused to say if he would use international law, or military law or federal statutes as guidelines. The chief military prosecutor, Air Force Col. Morris Davis, later said the judge can use several standards of law "to provide a full and fair trial."

Khadr has been charged with murder, attempted murder, aiding the enemy and conspiracy for allegedly throwing a grenade that killed a U.S. Special Forces soldier while fighting with the Taliban in Afghanistan and for planting mines targeted at American convoys.

Khadr is accused of killing Army Sgt. 1st Class Christopher Speer, 28, of Albuquerque, N.M., and wounding Army Sgt. Layne Morris, of West Jordan, Utah in the August 2002 firefight.

Nearly 500 detainees are held at the U.S. military base in southeastern Cuba. The United States has filed charges against 10 of them.