GUANTANAMO BAY NAVAL BASE, Cuba — Khalid Sheikh Mohammed and four other men charged with coordinating the Sept. 11 attacks said they want to enter guilty pleas, apparently challenging the U.S. government to sentence them to death before President-elect Barack Obama takes office.

The Guantanamo detainees said they decided on Nov. 4 — the day Obama was elected — to abandon their defenses in their death-penalty trials. Obama opposes the military war-crimes trials and has pledged to close Guantanamo's detention center, which holds some 250 men.

Mohammed said Monday he will confess to masterminding the attacks that killed 2,975 people. The four other defendants did the same, in effect daring the Pentagon to give them death sentences.

The judge ordered lawyers to advise him by Jan. 4 whether the Pentagon can apply the death penalty — which military prosecutors are seeking — without a jury trial.

Mohammed, who has already told a military panel he was the mastermind of the Sept. 11 attacks, said he has no faith in the judge, his Pentagon-appointed lawyers or President George W. Bush.

Sporting a chest-length gray beard, Mohammed told the judge in English: "I don't trust you."

The defendants' announcement shocked victims' relatives who watched from behind a glass partition, the first time family members have been allowed to observe the war-crimes trials.

Alice Hoagland of Redwood Estates, Calif., told reporters that she hopes Obama, "an even-minded and just man," would ensure the five men are punished, though she believes they should not be executed and become martyrs.

Hoagland's son, Mark Bingham, died on United Flight 93, whose passengers fought hijackers before it crashed in rural Pennsylvania.

But Hamilton Peterson, of Bethesda, Md., and whose father and stepmother died on United 93, said the defendants showed a "complete lack of contrition" and deserved to be executed.

Maureen Santora, of Long Island City, N.Y., watched from the back of the courtroom, wearing black and clutching a photograph of her son Christopher, a firefighter who died responding to the World Trade Center attacks.

"They were proud to be guilty and that says a lot about them," she said.