US President George W Bush has denied that the United States government is spying on the personal lives of what he called 'innocent Americans'.
He was responding to media reports that the US National Security Agency has been secretly monitoring millions of private phone calls made inside the country.
Mr Bush told reporters at the White House that the authorities did not listen into phone calls without court approval.
Both Democrat and Republican congressmen have expressed alarm at revelations that the NSA was building an unprecedented database of phone records with the help of three major US telephone companies.
The report follows revelations in December that Mr Bush authorised eavesdropping on telephone calls to foreign destinations without warrants from a special court.
Federal laws forbid the NSA from spying on US citizens without court approval.
Hayden nomination complicated
Bipartisan outrage over the report is likely to complicate the nomination of former Air Force General Michael Hayden as head of the CIA.
Mr Hayden headed the NSA from March 1999 to April 2005. The eavesdropping and database monitoring efforts took place during this time.
While the eavesdropping program revealed in December affected thousands of US citizens, the program outlined today details an NSA database of tens of millions of US phone customers.
The USA Today newspaper quoted sources as saying the NSA analysed the calling patterns of records provided by the AT&T, Verizon and BellSouth companies.
