'The numbers are what they are, which is they're troubling. This is why we are having to take such bold actions which we are taking,' White House spokesman Dana Perino told reporters aboard Air Force One.
The government on Tuesday revised down its earlier estimate of a downturn of 0.3 per cent in the world's largest economy.
'We think one of the reasons that the data sort of declines is that consumers pulled back on spending and we think a lot of that is because of the credit crisis, which is why we are so focused on un-freezing credit markets,' Ms Perino added.
Tuesday's latest revision by the Commerce Department was in line with forecasts by private economists and reflected weaker consumer spending, exports and government expenditures.
The report reflected an abrupt turn from growth of 2.8 per cent in the second quarter, although analysts said that figure was skewed by a surge in exports and consumer spending boosted by one-time tax rebates.
Many economists say the downturn in the fourth quarter could be much worse, reflecting a credit crunch and ongoing woes in housing and manufacturing.
The latest revised report showed consumer spending - which accounts for around 70 per cent of US economic activity - fell at 3.7 per cent pace, the steepest decline since 1980. That compared with an earlier estimate of a 3.1 per cent drop. --