House Democrats "will make sure that the full faith and credit of the United States of America is protected and preserved," Jeffries said at a media conference, adding, "The House will not allow the United States government to default on its obligations for the first time in American history."
Jeffries said Republicans have voted in the past to raise the debt limit and should do so now.
Republicans, who lost the White House in 2020 and lost majorities in the House and Senate, have told Democrats to raise the debt limit without their help.
The current U.S. debt ceiling already has been breached, with debt at $28.78 trillion. It is being financed temporarily through Treasury Department "extraordinary measures" that are projected to be exhausted in October.