The US has seen the first decline in employment since August 2003, providing fresh evidence that the US economy could be entering a recession.
Jobs have been cut in many industries
Employers cut 17,000 jobs from their payrolls in January, Labor Department figures showed. Economists had been expecting a rise of 80,000.
The US economy has slowed sharply in recent months as a housing market slump has dented consumer spending.
US interest rates have been cut twice in nine days to boost growth.
In a speech in Kansas on Friday, President George Bush acknowledged that the US economy was going through a rough patch and urged lawmakers in Washington to pass an economic stimulus package.
"Inflation's low. Productivity's high, but there are certainly some troubling signs, serious signs that the economy is weakening and that we've got to do something about it," Mr Bush said.
US Congress and the Bush Administration have agreed an economic stimulus package which would add $150bn in tax rebates.
The measure has already been passed by the House of Representatives but is still awaiting Senate approval.
The job losses were across all sectors of the economy including manufacturing and professional services.
"The economy is in recession mode," said Peter Morici, an economist at the University of Maryland.
The unemployment rate fell to 4.9% from 5% in December, a two-year high, but overall the number of people in the labour force declined.
The Federal Reserve cut interest rates to 3% from 3.5% on Wednesday.
It followed an emergency unscheduled cut last week, when the Fed slashed the cost of borrowing by the largest amount in 25 years to prevent the economy from slowing further.
"We should expect to see more bad news on the labour market, at least through the middle of the year, before the heavy doses of monetary and fiscal stimulus begin to kick in," said Nigel Gault, an economist at Global Insight.