US congressional leaders have agreed on a $US900 billion ($A1.2 trillion) package to provide the first new aid in months to an economy and individuals battered by the surging coronavirus pandemic.
The package would be the second-largest economic stimulus in US history, following a $US2.3 trillion aid bill passed in March.
It comes as the pandemic accelerates, infecting more than 214,000 people in the country each day. More than 317,000 Americans have already died.
"At long last, we have the bipartisan breakthrough the country has needed," Republican Senate Majority Leader Mitch McConnell said on the Senate floor on Sunday, following months of contentious debate.
Republican and Democratic leaders said the package should have enough support to pass both chambers of Congress.
President Donald Trump supports the bill and will sign it into law, White House spokesman Ben Williamson said.
The package would give $US600 direct payments to individuals and boost unemployment payments by $US300 a week. It also includes billions for small businesses, food assistance, vaccine distribution, transit and healthcare.
It extends a moratorium on foreclosures and provides $US25 billion in rental aid.
"Anyone who thinks this bill is enough does not know what's going on in America," Democratic Senate leader Chuck Schumer said at a news conference.
He said he would push for more aid after Democratic President-elect Joe Biden takes office on January 20.
Lawmakers said they had resolved disputes over the Federal Reserve's pandemic lending authority and other issues that had forced negotiations into the weekend.
The Democratic-led House of Representatives will likely vote on the package on Monday, with the Republican-controlled Senate to follow, according to House Democratic leader Steny Hoyer.
Congress aims to include the coronavirus aid package in a $US1.4 trillion spending bill funding government programs through September 2021.
But government funding is due to expire at midnight Sunday.
The House voted 329-65 to extend funding through Monday, buying more time to pass the coronavirus package and the larger government spending bill. The Senate must approve the temporary spending bill on Sunday, and Trump must sign it into law, to avoid disruption.
The relief bill leaves out two of the most contentious elements in the negotiations: legal protections for businesses from coronavirus lawsuits, which had been sought by Republicans, and the substantial aid for state and local governments advocated by Democrats.
But the package helps state and local governments indirectly by providing billions for schools, coronavirus testing and other expenses, Schumer said.
The bill would allow Federal Reserve emergency lending programs to expire on December 31 for businesses and state and local governments, which Republicans said were an unnecessary government interference in private business.
But it does not prevent similar programs from being created.