A military judge on Friday postponed the first war crimes tribunal at Guantanamo Bay, saying he wants to wait until the Supreme Court makes its highly anticipated ruling on the right of detainees to challenge their confinement in civil courts.

Navy Capt. Keith Allred ruled the trial for Osama bin Laden's former driver should be delayed seven weeks, until July 21, in case the Supreme Court ruling affects his case. He scheduled pretrial hearings to begin a week earlier.

A Supreme Court ruling is expected by June 30.

Defense lawyers for Salim Ahmed Hamdan, whose trial was scheduled to start June 2, had requested a postponement. Military prosecutors had said they were eager to go to trial.

The military judge's ruling is the latest in a series of delays for the government as it tries to prosecute Hamdan, a Yemeni, for acting as bin Laden's personal driver in Afghanistan, helping him to evade U.S. retribution following the Sept. 11 attacks.

An arraignment for the confessed mastermind of the Sept. 11 attacks, Khalid Sheikh Mohammed, and four other alleged plotters is scheduled for June 5 at the U.S. Navy base in southeast Cuba.

A Pentagon spokesman said Friday there are no plans to postpone the arraignment because of the Hamdan case ruling.

Allred said in his ruling that the postponement gives the prosecutors and defense "the benefit of a decision that may well change the tenor or conduct of the trial."

A delay, he said, also avoids the "potential embarrassment, waste of resources and prejudice to the accused," if the Supreme Court ruling forces a halt to the proceedings mid-trial.

"The accused has been in confinement for six years, and another month's wait will not prejudice any party to the case," Allred wrote.

Defense lawyer Andrea Prasow said the delay was welcome.

"We specifically sought the continuance and are very pleased that the judge agrees that all parties will benefit from the Supreme Court's guidance regarding the applicability of the Constitution to detainees held at Guantanamo," she said in an e-mail to The Associated Press.

In a separate ruling, the judge ordered a psychiatric evaluation for Hamdan to determine if he is competent to stand trial. A psychiatrist hired by his lawyers found he suffers from depression and post-traumatic stress disorder and cannot participate in his defense. The military says he has no signs of any mental problems.

Hamdan is charged with supporting terrorism and faces life in prison if convicted. His attorneys do not dispute that he was a driver for the al-Qaida leader, but insist he was just a low-level employee who had no role in planning or carrying out attacks against the U.S.

The U.S. holds about 270 prisoners at Guantanamo and has said it plans to bring about 80 before the tribunals _ the first to be held by the United States since the World War II era. One detainee has been convicted: David Hicks, who under a plea deal served a nine-month prison sentence in his native Australia.

The Supreme Court is considering a challenge to a provision of the Military Commissions Act of 2006 that denies Guantanamo detainees the right to file petition of habeas corpus.

Habeas corpus is a centuries-old legal principle, enshrined in the Constitution, that allows courts to determine whether a prisoner is being held illegally.

The government says foreigners held outside the United States have no constitutional rights and that Congress has stripped federal courts of jurisdiction in the detainee cases.

The pending case before the court is the third time the Supreme Court has examined the rights of the detainees.

Twice before, the court has ruled against the administration. Each time Congress and the White House have changed the law in an effort to keep the Guantanamo prisoners from contesting their detention before American judges.