President George W. Bush denied last night that the government was "trolling through" Americans' personal lives, despite a report that a domestic spy agency was collecting phone records of tens of millions of citizens.
Defending his administration's espionage program, Mr Bush said intelligence activities he had authorized were lawful and the government was not eavesdropping on domestic calls without court approval.
But Democrats and Republicans alike demanded an explanation after USA Today reported the National Security Agency was secretly amassing phone records from phone companies to analyze calling patterns in an effort to detect terrorist plots.
"The privacy of ordinary Americans is fiercely protected in all our activities," Bush told reporters at a hastily called session aimed at damage control. "We're not mining or trolling through the personal lives of millions of innocent Americans."
Some senators suggested, however, the disclosure could complicate confirmation of Air Force Gen Michael Hayden, who was nominated by Bush on Monday as director of the CIA.
USA Today said Gen Hayden, who headed the NSA from 1999 to 2005, would have overseen the call-tracking program.
The White House said Gen Hayden's nomination was going "full steam ahead."
"Everything that NSA does is lawful," Hayden insisted after meeting Sen. Mitch McConnell, a Republican from Kentucky, as he pressed ahead with visits to senators who will consider his appointment.
The controversy could compound Bush's political problems as he struggles to lift public approval ratings that have fallen to new lows, putting his Republican party's control of Congress at risk in November's elections.
Revelation late last year that the NSA was eavesdropping inside the United States without warrants on international calls and e-mails of terrorism suspects sparked an uproar.
But the USA Today report, if confirmed, means the agency's domestic program has been on a far wider scale.
Before leaving for Biloxi, Mississippi, a stern-faced Bush said: "Our efforts are focused on links to al Qaeda and their known affiliates" to prevent future attacks. But he did not confirm or deny the USA Today story.