GUANTANAMO BAY, Cuba - A Canadian detainee at Guantanamo sought to dismiss his U.S. military defence attorneys Monday, saying he lost trust in the lawyers after seeing them fight among themselves in one of the highest-profile war crimes cases.

The complaint from Omar Khadr, who is charged with killing an American soldier in Afghanistan, came in the first open session of the Guantanamo tribunals since President Barack Obama put them on hold in January.

"I can't trust these lawyers. They've been accusing each other for the last four months and fighting in front of me," said Khadr, who had a full black beard and wore a white prison jumpsuit.

The new signs of turmoil at the hearing in a hilltop courthouse overlooking the Caribbean suggest Obama's timetable for closing the offshore prison is overly optimistic.

Obama has pledged to keep the military tribunals for at least some Guantanamo detainees, but the dispute in one of the longest-running cases shows how even small issues can stall the lightly tested system for prosecuting terror suspects.

Officials say the president will likely need to extend his self-imposed January deadline to close Guantanamo or move the trials elsewhere.

Khadr, who was 15 years old when he was detained in 2002, said he trusts only his Canadian lawyers and he wants them to choose who should defend him against war crimes charges that include murder and conspiracy. The judge, Army Col. Patrick Parrish, said Khadr could meet with those attorneys before making a final decision.

Parrish called the hearing to resolve infighting on the defence team over who has the right to dismiss an attorney.

The chief defence counsel, Air Force Col. Peter Masciola, has been trying since April to fire the lead attorney for Toronto-born Khadr, Navy Lt. Cmdr. William Kuebler, whose aggressive defence and impromptu news conferences have riled military superiors. Kuebler insists Masciola can't dismiss him without the trial judge's permission.

Neither side has discussed the dispute in detail. But Kuebler says Masciola wants to oust him over strategy disagreements, while Masciola has called Kuebler's leadership of the defence team "dysfunctional."

Khadr, 22, said he cannot trust any U.S. lawyer after being exposed to the squabbling, including an argument Monday morning.

The son of a slain al Qaeda financier, Khadr faces a maximum life sentence if convicted. He is accused of killing U.S. Army Sgt. 1st Class Christopher Speer of Albuquerque, New Mexico, with a grenade during a 2002 battle at an al Qaeda stronghold in Afghanistan.

The judge was also due to address a request from Obama for a new 120-day suspension, issued in all pending commissions cases, that would keep them on hold until mid-September. The president wants the time to review strategy for prosecuting terror suspects and introduce changes to the tribunal system that he says will give detainees stronger legal protections.

So far, judges have agreed to the extension for nine of the 11 detainees facing charges at Guantanamo.