After being held for more than three years by the Navy as an "enemy combatant," an American accused of being an Al Qaeda operative will begin constructing his defense as a civilian.

Jose Padilla who was transferred from military to civilian custody Thursday, had been scheduled to return to federal court Friday to enter a plea, but a judge postponed that step until Jan. 12.

A judge will determine whether the former Chicago gang member will remain in custody or be released on bail. Prosecutors said they would seek for him to be held before his trial.

Padilla is accused of joining a North American terror-support network that sent him overseas to train with Al Qaeda and to "murder, maim and kidnap" people on foreign soil. He was taken from a South Carolina brig and flown to Miami on Thursday.

Padilla was arrested at Chicago's O'Hare Airport in May 2002 and held by the Bush administration without criminal charges on suspicion of plotting to detonate a radioactive "dirty bomb" inside the United States.

The Supreme Court has been asked to use Padilla's case to define the extent of presidential power over U.S. citizens who are detained on American soil on suspicion of terrorism. But before the high court could decide whether to take up the case, the Bush administration indicted Padilla in November in civilian court. The charges do not involve the "dirty bomb" allegations.

At a brief hearing Thursday, U.S. Magistrate Judge Barry Garber explained Padilla's rights as a criminal defendant and asked whether he understood them.

"Yes, I do," said Padilla, dressed in an orange prison jumpsuit and shackled at the wrists and ankles. He wore glasses and had a short haircut.

Padilla's transfer to civilian custody was approved Wednesday by the Supreme Court, which overruled the 4th U.S. Circuit Court of Appeals.

The appeals court had refused to allow the transfer in a decision sharply critical of the Bush administration. It suggested the administration changed tactics and indicted Padilla to avert a ruling from the Supreme Court on presidential powers during wartime.

Padilla is an alleged recruit of two defendants in a Miami terror case. Kifah Wael Jayyousi, a Jordanian who has U.S. citizenship, and Adhan Amin Hassoun, a Lebanese-born Palestinian, are accused of raising money and recruiting operatives to fight for radical Islamic causes in Bosnia, Kosovo, Chechnya and elsewhere. Their trial is expected to start in the fall.

Jayyousi also appeared in federal court Thursday. U.S. District Judge Marcia Cooke ordered that he be released on bail and set a $1.3 million bond. She also ordered electronic monitoring and that Jayyousi not leave the South Florida area. He has been in solitary confinement since his arrest in March.