The government is more interested in questioning a U.S. citizen accused of plotting to detonate a radioactive weapon than in pursuing charges against him, Defense Secretary Donald H. Rumsfeld says.

"We're not interested in trying him at the moment," said Rumsfeld, traveling in Qatar. "We're not interested in punishing him at the moment. We're interested in finding out what in the world he knows."

Rumsfeld's remarks came just after the U.S. military indefinitely imprisoned as an "enemy combatant" Jose Padilla, 31, also known as Abdullah al Muhajir. President Bush over the weekend approved Padilla's unorthodox transfer from custody of the Justice Department, where he had been held secretly as a material witness since his May 8 arrest.

Attorney General John Ashcroft, meeting in Budapest on Tuesday with justice officials, said Padilla's detention was "the right course of action."

The White House disclosed Padilla's capture on Monday, just before a federal court hearing in New York to determine whether the Justice Department could continue holding Padilla. At that hearing, which occurred Tuesday, the judge hinted that questions over the propriety of Justice officials holding Padilla were moot, since Padilla already had been turned over to the Defense Department.

Padilla's lawyer, Donna R. Newman, said outside court that he denied the government's allegations. She also indicated she will appeal the decision to place Padilla in military custody.

Government lawyers said Tuesday that under a 1942 Supreme Court ruling, even Americans who fight against the United States are subject to military courts — but only if they enter the country. The court's decision, from six decades ago, focused on "armed prowlers" who blow up bridges or cut telegraph wires.

Padilla, a former gang member in Chicago who converted from Catholicism to Islam after run-ins with the law, is accused of traveling to Afghanistan and Pakistan and meeting with senior al-Qaida leaders after the Sept. 11 attacks.

U.S. officials, speaking on condition of anonymity, said Padilla used the Internet at a home in Lahore, Pakistan, to learn how to build a "dirty bomb" that could spread radioactive material over dozens of city blocks. Authorities believe he was traveling to the United States to scout locations for bombings.

Dirty bombs combine traditional explosives with radioactive material. Such a weapon would not create a nuclear explosion, but could release small amounts of radiation over parts of a city.

Bush described Padilla as one of many "would-be killers" in U.S. custody.

"There's just a full-scale manhunt on," Bush said in a Cabinet Room meeting on his proposed overhaul of homeland security agencies. "We will run down every lead, every hint. This guy Padilla's a bad guy and he is where he needs to be, detained."

Rumsfeld said filing charges against suspected terrorists might not help protect Americans from terror attacks.

"What our country and what other countries have to think of is, what's your priority today?" Rumsfeld said Tuesday. The defense secretary was on his way to New Delhi, India, to try to ease tensions between India and Pakistan.

Padilla, whose criminal history in America includes convictions at age 14 from a street fight that left one man dead, traveled to Chicago on May 8 from Pakistan via Cairo and Zurich, Switzerland, a U.S. official said. He was arrested at O'Hare International Airport.

Padilla apparently lost his passport in Karachi in February and sought a new one, State Department spokesman Richard Boucher said. The government complied in March but tipped off the FBI and CIA about Padilla's location and his request.

Padilla was carrying more than $10,000 cash, believed to have come from al-Qaida, possibly while he was in Switzerland, a government official said Tuesday. Swiss authorities confirmed they were investigating Padilla's visit to their country.

In a related development, U.S. and German officials said they have identified a German citizen of Syrian origin who recruited Mohammed Atta and other Sept. 11 hijackers into al-Qaida, The Washington Post reported in its Wednesday editions.

The suspect, Mohammed Haydar Zammar, has been missing since October, but an official told the Post the Germans suspect he is in U.S. custody or being detained in another country at the United States' request.