Attorney General Alberto Gonzales said Friday he would testify in Senate hearings about the National Security Agency's domestic surveillance program, but said his discussions would be limited to the legal authority behind it.

"As the president indicated yesterday, the absolute worst thing we could do is talk about the operational aspects of a highly classified program that has been very successful in protecting America, and divulge all that information to the enemy. So what I'm going to do is come before the Senate Judiciary Committee and talk about the legal authorities in connection with this program," Gonzales said.

Senate Judiciary Committee Chairman Arlen Specter, R-Pa., said earlier this week that he asked Gonzales to testify publicly, and that he hopes to begin hearings in February.

Gonzales' comments came in response to questions from reporters after he addressed the end of hearings over Supreme Court nominee Samuel Alito during a news conference Friday.

There has been a growing furor over the admission by President Bush that he authorized the NSA to monitor phone calls and e-mails of people who communicate with suspected Al Qaeda members or its associates without a warrant. The monitored communications either originated on U.S. soil to overseas, or vise versa, and could have involved American citizens.

Alito was asked numerous questions by the Senate Judiciary Committee this week about whether the president has the constitutional authority to go over Congress' head and authorize such eavesdropping procedures inside the United States.

Critics say the authorization is in direct contrast to standing law. The Foreign Intelligence Surveillance Act requires judicial review of domestic wiretaps. But administration officials, including Gonzales, have said there is authority to run the NSA program in constitutional executive powers and under the congressional authorization of force approved after the Sept. 11, 2001, terrorist attacks. The administration argues that the resolution gave the president the authority to do whatever it takes to protect Americans and the country.

Gonzales, who was White House counsel when the president first authorized the NSA program, said Friday there had been a number of lawyers involved in the program and he would use his time before the Senate to further explain why the administration believes it has the authority to run the program.

"We believe the legal authorities are there, and that the president acted consistent with his legal authorities in a manner that he felt was necessary and appropriate to protect this country against this new kind of threat," Gonzales said.

The Justice Department is probing who first leaked details of the program to The New York Times, which first reported the story in December; in general, it's against the law to knowingly leak classified information.

Answering a question about the probe into that leak, Gonzales said it's too early "to make [a] decision regarding whether or not reporters should go to jail."

But, he said, "We have an obligation to ensure that our laws our enforced. There's been a serious disclosure of classified information that's occurred in connection with this case and obviously, we're going to look at it very, very seriously."