GUANTANAMO BAY NAVAL BASE, Cuba - Five men charged with plotting the Sept. 11 attacks have told a U.S. military judge that they want to immediately confess at their war-crimes tribunal.

The confessions seem likely to result in guilty pleas at the trial at the U.S. military prison camp in Guantanamo Bay, Cuba.

All five face possible execution if convicted.

They say they decided to abandon all efforts to defend themselves on Nov. 4, the day Barack Obama was elected to the White House.

Observers say it's as if they want to rush toward convictions before Obama takes office.

The president-elect has vowed to end the war-crimes trials and close the Guantanamo prison camp.

In a letter the judge read aloud in court, the five defendants said they "request an immediate hearing session to announce our confessions."

The letter implies they want to plead guilty, but does not specify whether they will admit to any specific charges.

The judge, army Col. Stephen Henley, said competency hearings were pending for two of the detainees, precluding them from immediately filing pleas.

Henley asked Khalid Sheikh Mohammed and his co-defendants if they were prepared to enter a plea. So far, Mohammed and three others said they agreed with the letter; the fifth remained to be questioned by the judge.

Mohammed, who has already told interrogators he was the mastermind of the Sept. 11 attacks, also told the judge Monday that he had no faith in him, his Pentagon-appointed lawyers or President George W. Bush.

Sporting a chest-length grey beard, Mohammed said in English: "I don't trust you."

The pretrial hearings this week could be the last court appearance for the high-profile detainees at Guantanamo Bay.

The first U.S. war-crimes trials since the Second World War are teetering on the edge of extinction. Obama opposes the military commissions -- as the Guantanamo trials are called -- and has pledged to close the detention centre that still holds some 250 men soon after taking office next month.

Nine relatives of victims of the 2001 al-Qaida attacks were on hand to observe the hearings at the naval base in southeastern Cuba, but were not visible in video images relayed to a press room nearby. Five were chosen by military lottery and they brought four other relatives with them.

Henley was assigned to the case after the previous judge resigned for undisclosed reasons in November. The defendants, who are representing themselves, were also expected to question Henley about whether any conflicts would prevent him from impartially overseeing the death-penalty case.

No trial date has been set, and it is all but certain none will begin before Obama takes office on Jan. 20. Still, the U.S. military is pressing forward with the case until it receives orders to the contrary.

"We serve the sitting president and will continue to do so until president-elect Obama takes office," said navy Cmdr. Jeffrey Gordon, a Pentagon spokesman.

Jennifer Daskal of Human Rights Watch, who is also an observer at this week's hearings, urged Obama to try terror suspects in federal court "where attention will focus on the defendants' alleged crimes rather than the unfairness of the commissions."

The military commissions have netted three convictions, but have been widely criticized for allowing statements obtained through harsh interrogations and hearsay to be admitted as evidence.