Jen Psaki, the White House press secretary, told reporters that the president had decided to focus in the negotiation on plans that “should be completely acceptable to a number of Republicans who said that they — they want to leave — their bottom line is they want to leave the 2017 tax law untouched.”
She later added that raising the corporate tax rate above 21 percent was still a key goal.
The discussions have unsettled some progressive Democrats, who are pushing Mr. Biden to abandon talks and move his economic plan through the budget reconciliation process, which would allow it to pass with only Democratic votes. They questioned whether a compromise struck with Ms. Capito could secure the 10 Republican votes needed to pass a bill through normal Senate procedures and argued that Republicans had done little to move closer to the White House on the amount of new spending or how to finance it.
“No Republican vote in favor of an infrastructure package should supersede our mission: to build an America that works for the people, not for massive corporations,” Representative Jamaal Bowman, Democrat of New York, said in a statement. “Getting Republicans on board is not necessary. Getting the American people back on their feet is.”
Republicans have complained that Mr. Biden is not willing to reduce his spending demands to a degree they could support, and they have been surprised at his continued resistance to raising gas taxes and other fees that have traditionally supported some infrastructure programs. As of Thursday afternoon, it was unclear whether Republicans would compile another counterproposal.
Both sides have a stake in prolonging the negotiations.
Mr. Biden is seeking to achieve bipartisanship or exhaust its possibilities, in part to secure votes from Democratic senators like Joe Manchin III of West Virginia and Kyrsten Sinema of Arizona, who have insisted on including Republicans in the infrastructure effort.
“At any moment, it’s very possible the Republicans say, ‘Wait a minute, either we’re going do it our way or we’re not going do it at all,’” said Senator Benjamin L. Cardin, Democrat of Maryland. The next 10 days would be critical, he said. “It’s also possible the Democrats are going to say, ‘You do it our way all, and if not we’ll go through it ourselves.’ I hope that’s not the case.”
Leading Democrats say a compromise that falls short of Mr. Biden’s ambitions could pave the way for a reconciliation bill that includes many of the spending proposals and tax increases in his broad agenda, like affordable child care, universal prekindergarten and additional efforts to fight climate change.