The U.S. military's highest court is asking WikiLeaks to explain why the military justice system, rather than civilian courts, is the proper venue for seeking routine judicial documents in the court-martial of an Army private charged with giving classified information to the secret-spilling website.

The jurisdictional issue was the first question raised by the Court of Appeals for the Armed Forces during an hour of oral arguments Wednesday in Washington. The panel of five civilian judges heard arguments on the main dispute but made it clear that the court must first be convinced it has jurisdiction.

Lawyers from the Center for Constitutional Rights and the government said they would submit briefs before the end of the month on that question. The New York-based civil-rights group is representing WikiLeaks, its founder Julian Assange and several left-leaning pundits and publications including The Nation magazine and the broadcast operation Democracy Now.

The Associated Press is among 30 news organizations supporting the appeal in a brief filed by the Reporters Committee for Freedom of the Press. They agree with the appellants that the First Amendment requires timely public access to written documents such as motions and rulings in Pfc. Bradley Manning's court-martial.