According to people familiar with the talks, Democrats abandoned plans to include a paid-leave programme in their social spending and climate bill, while prospects for a billionaires' levy to help fund the package faded and a potential surtax on wealthy Americans' income gained traction.

The White House is urging Democrats to unite behind the bill, which is expected to cost around $1.75 trillion, by the end of the week, which could pave the way for the passage of a parallel bipartisan infrastructure package that has been stalled in the House by progressives. President Biden is scheduled to attend the Glasgow Climate Conference next week, and the gubernatorial elections in Virginia and New Jersey conclude on Tuesday, making the White House eager to demonstrate progress on his agenda.

On Wednesday morning, White House officials met with two critical centrists, Sens. Joe Manchin (D., W.Va.) and Kyrsten Sinema (D., Ariz.), while Mr. Biden met with influential progressive Sen. Bernie Sanders (I., Vt.).

By late Wednesday night, no agreement had been announced. Mr. Biden was scheduled to visit Capitol Hill on Thursday morning to address House Democrats and then deliver remarks from the East Room before departing for Europe.

Senate Majority Leader Chuck Schumer (D-NY) stated that a deal could be reached soon. House Speaker Nancy Pelosi (D-Calif.) announced in a public letter that Democrats would begin the formal consideration of the legislation on Thursday.

In one significant change, Democrats removed the paid-leave proposal from the bill. Originally intended to last 12 weeks, lawmakers attempted to shorten the programme to four weeks in order to overcome centrist opposition, but the measure was ultimately dropped, according to people familiar with the matter.