The US Senate on Wednesday afternoon overwhelmingly approved a measure to extend Bush-era tax cuts on all Americans, including the rich, for an additional two years.

The vote was 81-19 on the $858 billion legislation, framed on a bipartisan deal struck between President Barack Obama and Senate Republican Leader Mitch McConnell (KY). It also extends unemployment benefits for 13 months and cuts the Social Security payroll tax and estate tax.

The White House still faces opposition over the compromise from House Democrats, who have rebelled against extending the high-end tax breaks and expressed concerns about the estate tax reduction. Some liberals also fear lowering the payroll tax could threaten Social Security.

Speaker Nancy Pelosi (D-CA) and others including Rep. Chris Van Hollen (D-MD) have publicly said the House will not approve the deal without some changes, most likely to the estate tax.

The general framework of the deal is expected to be approved despite seemingly irreconcilable differences between the House and Senate, as Republicans have threatened to block any bill that excludes the high-income tax cuts and Democrats are wary of scuttling a middle-class tax break.

The House is expected to vote on the measure as early as Thursday.

Polls say the compromise is popular with the public, and the White House is forcefully pressing Congress to approve a deal in order to prevent a tax hike on all Americans, which would occur on Jan. 1 if no action is taken.

"I know there are different aspects of this plan to which members of Congress on both sides of the aisle object," Obama said Thursday. "That's the nature of compromise. But we worked to negotiate an agreement that's a win for middle-class families and a win for our economy, and we can't afford to let it fall victim to either delay or defeat.''