S&P downgrade US AAA credit rating

One of the top credit rating agencies, Standard & Poor's, has downgraded the United States' top-notch AAA rating for the first time.

S&P cut the long-term US rating by one level to AA+ with a negative outlook, citing concerns about budget deficits.

President Obama is said to have been told in advance of the downgrade but the White House says the analysis of the American economy contains serious errors.

Marcus George reports.