US Senators have agreed on a $780 billion emergency stimulus package to revitalise the country's spluttering economy.

A small group of minority Repubicans crossed party lines to support the bill.

The package, which falls about $100 billion short of the initial bill, had passed through the lower house of representatives with only democrats voting in favour.

Senator Susan Collins of Maine, who was one of three Republicans to join the Democrats when the bill was debated in the upper house. She pledged her vote because of the need to avoid “partisan gridlock”.

“They want to see us working together to solve the most important crisis facing our country,” Collins said.

A majority of the spending will go towards victims of the recession by way of unemployment compensation, health care and food stamps.

In spite of concessions by Democrats to bring the overall price tag of the bill down, some Republican critics argue that the bill could end up costing just as much if not more.

“It is as expensive or more expensive than the legislation passed by the House, if you count the amendments that have already been passed,” Republican Senator and former presidential candidate John McCain said.

Friday's agreement was the culmination of a long day of backroom negotiations, with Senate Majority Leader Harry Reid and White House Chief-of-Staff Rahm Emanuel working to attract enough votes to meet the 60-vote requirement.

Obama had also applied pressure by calling the delay in congress “inexcusable and irresponsible” in light of the new unemployment report which said U.S. unemployment had risen to 7.6 per cent, the worst since September 1992, and that January had seen a loss of 598 thousand jobs.

The bill had already passed through the House with Republicans unanimously rejecting it. However, with the new agreement reached, a final vote in the next couple of days should send the bill to President Obama's desk.

The legislation includes funds for highway and bridge construction as well as the creation of a new health technology industry and so-called green jobs to encourage independence from imported oil.