The United States filed papers Friday in two more federal lawsuits filed over the National Security Agency terrorist surveillance program, invoking the state secrets privilege to have the lawsuits dismissed.

The Center for Constitutional Rights had filed a lawsuit in New York, and the American Civil Liberties Union had filed a lawsuit in Detroit, against the U.S. government, each alleging that the NSA illegally intercepted the telephone calls of American citizens without warrants.

President Bush confirmed the existence of the program in December, and maintains that he has the legal authority to order interception of telephone calls without warrants while looking for terrorists.

Director of National Intelligence John D. Negroponte invoked the state-secrets privilege on behalf of the administration, writing that disclosure of such information would cause “exceptionally grave damage” to national security.

The administration laid out some of its arguments in classified memos that were filed under seal. . . .

Justice Department attorneys said in their legal brief that the legality of the president’s actions could be properly judged only by understanding “the specific threat facing the nation.” They noted: “That understanding is not possible without revealing to the very adversaries we are trying to defeat what we know about them and how we are proceeding to stop them.” — Associated Press

In April, the government also invoked the state secrets privilege in a lawsuit filed against AT&T by the Electronic Frontier Foundation alleging that the company had provided technical assistance to the NSA to implement the terrorist surveillance program in violation of law.