"This is one of most significant downward quarters for jobs in post World War history."

Stimulus plan

The number of unemployed rose to 11.1 million in December, the data showed.

The Labour Department also revised the number of job losses for the prior two months, with the October figure being changed to show a loss of 423,000 jobs from 320,000 and November a loss of 584,000 from 533,000.

The report, seen as perhaps the best indicator of economic momentum, "suggests that both the US economy and job market fell off a cliff" at the end of 2008, said Nariman Behravesh, the chief economist at IHS Global Insight, a financial research firm.

Behravesh said he expected "the jobs hemorrhage to continue through much of 2009" at a heavy pace and to ease if a large economic stimulus package can be enacted quickly.

Barack Obama, the US president-elect, warned on Thursday that the struggling US economy could be in recession for years unless politicians agree a massive economic stimulus plan.

Obama, who takes office on January 20, has pledged to change US economic policy, and is set to introduce a new stimulus plan containing tax cuts and public spending that could total almost $800bn.