Biden and his aides spent the weekend working to get the infrastructure deal back on track.

Politics|Biden and his aides spent the weekend working to get the infrastructure deal back on track.

A fragile bipartisan infrastructure deal appeared to be moving forward once again on Sunday, as moderate Republicans said they had been reassured that President Biden would not hold it hostage while Democrats simultaneously work on a larger, partisan economic package.

After 48 hours of chaos, the statements by leading Republicans prompted a sigh of relief for the White House, where Mr. Biden and top aides had worked through the weekend to keep the eight-year, $1.2 trillion investment to rebuild the nation’s infrastructure from falling apart. Republican negotiators even suggested that they could now begin drafting the bill and said they believed it would win enough Republican votes to pass the Senate next month.

“The waters have been calmed,” said Senator Mitt Romney, Republican of Utah.

Still, the whole episode underscored just how precarious a path the president and his allies face in the months ahead, as they try to steer the two separate and costly spending plans into law. They have laid out a complex strategy in which the success of each bill hinges on the other and the balancing of priorities between not only Republicans and Democrats, but within the Democratic Party itself.

The immediate cause for Republican concern came on Thursday, just hours after the president and lawmakers from both parties unveiled with great fanfare their plan to invest in crumbling roads, bridges, high-speed internet and green projects. Speaking with reporters later that day, Mr. Biden said he would not sign the bipartisan deal without Congress passing a much more expensive set of tax cuts and spending programs that conservatives loathe.

Republicans, who doubt Democrats can secure the votes needed to pass the second partisan package, balked. They said that they never would have signed onto a deal strictly conditioned on the success of policies they oppose, and Mr. Biden’s team was forced to clean up the comments. After a series of private phone calls, the president issued a lengthy statement on Saturday clarifying that he never meant to threaten a veto and conceding that Republicans were “understandably upset.”

“I was very glad to see the president clarify his remarks because it was inconsistent with everything we had been told along the way,” Senator Rob Portman, Republican of Ohio, said on ABC’s “This Week.”