"We have to Spy on you to protect your civil liberties"

George Bush admitted that he had personally authorized a secret eavesdropping program in the U.S. more than 30 times. "This is a highly classified program that is crucial to our national security," he said in his weekly radio address delivered live from the White House.

"The American people expect me to do everything in my power, under our laws and constitution, to protect them and their civil liberties and that is exactly what I will continue to do as long as I am president of the US."

Republican Senator Arlen Specter of Pennsylvania, chairman of the Senate Judiciary Committee, on Friday said the NSA program was inappropriate and he promised hearings soon.

James Bamford, author of two books on the National Security Agency, said the program could be problematic because it bypasses a special court set up by the 1978 Foreign Intelligence Surveillance Act to authorize eavesdropping on suspected terrorists.

"I didn't hear him specify any legal right, except his right as president, which in a democracy doesn't make much sense," Bamford said in an interview. "Today, what Bush said is he went around the law, which is a violation of the law - which is illegal."

"I tell you, he's President George Bush, not King George Bush. This is not the system of government we have and that we fought for," Senator Russell Feingold, D-Wis., told The Associated Press.

Susan Low Bloch, a professor of constitutional law at Georgetown University Law Center, said the president needs authorisation from Congress for this kind of activity.

"He's taking a hugely expansive interpretation of the Constitution and the president's powers under the Constitution," she said.