Gonzales stressed that the program is "narrowly focused" and that adequate steps are taken to protect privacy, though he said he was unable to describe such procedures because of the program's classified nature.
fields Senate questions on Monday.
The admissions came as part of the first of what will likely be several public hearings before the U.S. Senate Judiciary Committee. A full slate of Democrats and Republicans rotated 10-minute stints questioning Gonzales, the day's sole witness, about . A CNET News.com survey published Monday say they are not cooperating with the NSA.
The Bush administrationthat the program, which has transpired without prior court approval since shortly after the Sept. 11 attacks, only monitors communications in which at least one party is located outside the United States and is a member or agent of al-Qaida or groups associated with terrorists.
Meanwhile, it has stuck to a, which Gonzales outlined repeatedly on Monday: the U.S. Constitution, a Congressional resolution passed shortly after Sept. 11 that authorizes the use of military force against al-Qaida and its allies, and a Supreme Court interpretation of that resolution.
But Gonzales shunned all questions he deemed "operational" matters, such as how many people have been subject to the tapping, how the government goes aboutfrom a legal perspective, and whether additional secret surveillance programs have been authorized by the same logic.
"Can you assure us that no one is being eavesdropped upon in the United States other than someone who has a communication that is emanating from foreign soil by a suspected terrorist, al-Qaida or otherwise?" Sen. Joseph Biden, a Delaware Democrat, asked at one point early in the daylong hearing.
"I can't give you absolute assurance," Gonzales replied, before adding, "What I can assure the American people is we have a number of safeguards in place so we can say with a high degree of certainty that those procedures are being followed."
Democrats dominated the criticism about the program's lack of court authorization and suspected illegality, but Committee Chairman Arlen Specter, a Pennsylvania Republican, also strongly encouraged the attorney general to consider seeking court review for the entire program. "The concern is that there is a broad sweep which includes people who have no connection with al-Qaida," he said. "What assurances can you give to this committee and, beyond this committee, to millions of Americans who are vitally interested in this issue and following these proceedings?"
Said Gonzales, "The program as operated is a very narrowly tailored program, and we do have a great number of checks in place." He said later in the hearing that he was unable to give "specific information about collected, retained and disseminated" communications, except to say that it is done so "in a way to protect privacy interests of all Americans."