Speaker Nancy Pelosi of California and Steven Mnuchin, the Treasury secretary, spoke Wednesday about the prospects of a stand-alone bill for airline relief, as President Trump continued to walk back his own retreat from negotiations on a broader coronavirus relief package and to push for more narrow legislation.

During a conversation in the morning, Mr. Mnuchin asked about the possibility of a stand-alone bill, as a critical payroll program for airline workers lapsed last week and airlines have warned of tens of thousands of more furloughs and layoffs without federal intervention.

Ms. Pelosi noted that Democrats had already thrown their support behind such a measure and reminded Mr. Mnuchin that Republicans had objected to unanimous