President Bush is considering what charges, if any, should be filed against John Walker Lindh, the 20-year-old American who fought with the Taleban until he was captured last month. No decision is expected until American interrogators finish questioning Walker Lindh on what his role in Afghanistan was, including whether he supported the September terrorist attacks against the United States.

John Walker Lindh is being held as a battlefield detainee on board an American warship in the Arabian Sea, along with captured members of the al-Qaida terrorist network.

The White House has not decided whether a case can be made against him for treason. Spokesman Ari Fleischer tells reporters much more still needs to be known about his involvement with the Taleban. "The president hasn't ruled anything in or out because no determinations have been made and he hasn't received all the word yet from the investigators," he said.

U.S. interrogators have been questioning Mr. Walker since his capture last month in Mazar-e-Sharif but have said little about what he has told them, including whether he willfully fought with the Taleban or was forced to.

Republican Senator John McCain, a former prisoner of war in Vietnam, suspects that will be a key question when a decision about whether to prosecute is made. "If he fought against Americans, that is a very, very serious act. I'd like to see the first thing done with Mr. Walker is to take him to ground zero and show him ground zero and see how he feels after that," he said.

But former Navy criminal lawyer Greg Noone thinks treason will be a difficult charge to prove. "Treason has to have two witnesses. And I don't know if they want to go down that path," he said.

But prosecutors do have a range of options. "I think he will face some type of criminal charge, whether it will be treason or whether it will be a lesser charge of assisting terrorists or something along those lines. But I think he probably will face some type of charge," said Mr. Noone.

Mr. Walker's parents in California said their son was brainwashed and are asking Americans to withhold judgment until all the facts are known.