Three of the six US military officers sitting on the Guantanamo tribunal have been dropped after complaints of potential bias.
America has promised to provide fair military trials
The remaining three members of the tribunal will hear the cases of two terror suspects held at the Cuban camp, starting from 1 November.
A Pentagon spokesman confirmed that the trials would go ahead on schedule.
Defence lawyers have accused the head of the tribunal of bias but army Col Peter Brownback retains his position.
The names of those officers taken off the tribunal were not given.
However, John Altenburg, the Pentagon official overseeing the trial process, did give reasons for their removal.
He said two had been closely involved in the war on terrorism, which might "create a reasonable and significant doubt as to the ability of these two members to decide these cases fairly and impartially".
He said the third had made statements that raised questions about his ability to put aside his emotions during the trial.
Guantanamo Bay currently houses about 549 detainees, most of them thought to have been captured in action during the US-led war in Afghanistan.
The three-strong tribunal will now hear the cases of David Hicks of Australia and Salim Ahmed Hamdan of Yemen.
A lawyer for Mr Hicks, Josh Dratel, criticised the decision not to replace the dismissed panel members.
"A two-out-of-three vote is a conviction which is really insufficient in a case of this magnitude," he said.
Additional tribunal members will be provided for the subsequent trials of Ibrahim Ahmed Mahmoud al-Qosi of Sudan and Ali Hamza Ahmed Sulayman al Bahlul of Yemen, the Pentagon said on Thursday.
A spokesman confirmed that Mr Altenburg had declined to remove Col Brownback.
Earlier, defence lawyers, who are themselves Pentagon appointees, argued that the colonel was a personal friend of Mr Altenburg and could not be partial.
The Associated Press news agency said Mr Altenburg rejected complaints against two other tribunal members while there was no challenge to the sixth.