US President Barack Obama says the Senate's delay in passing his financial stimulus package is "inexcusable and irresponsible".
The Labour Department says 598,000 jobs were lost in the United States in January.
President Obama described the news as devastating, and said the economic situation could become "a catastrophe" if the Senate fails to act.
"The situation could not be more serious. These numbers demand action," he said.
"It is time for Congress to act. It is time to pass an Economic Recovery and Reinvestment Plan to get our economy moving again."
The stimulus package is valued at $US937 billion and includes tax cuts and investment in job creation.
Some Senators want cuts in the size of the package and a moderate group of Democrats and Republicans is trying to find a compromise.
They are reportedly trying to reduce the bill by about $US100 billion.
Majority Leader Harry Reid says progress has been made and he thinks a deal will be reached on Friday. However, Republicans have renewed their attacks on the bill.
Discussing the job figures, Senator Reid said the United States was not in a downturn like the Great Depression, when unemployment was 25%.
Mr Obama has rejected Republican arguments that the stimulus plan would dangerously expand the US budget deficit.
The House of Representatives passed a $US819 billion version of the stimulus measure last week without a single Republican vote.
Differences between the House and Senate versions of the legislation have to be worked out before the bill goes to Mr Obama. He wants the final bill on his desk by 16 February.
Democrats have 58 of the 100 seats in the Senate. They need 60 votes to bypass potential procedural roadblocks.