U.S. Treasury Secretary Jack Lew said he worries congressional bickering could cause a financial "accident," seriously hurting markets and damaging the overall economy.
Lew spoke Wednesday at the left-leaning Center for American Progress, saying Washington faces a "very real" November 3 deadline to increase the legal authority to borrow money to pay debts incurred by the government.
Without an increase in the debt limit, Lew said the treasury will be unable to fully pay many obligations, needlessly causing a loss of confidence in the government, discouraging investment, and leaving Washington without the means to cope with emergencies.
Lew said the debt limit should not be used as a weapon in separate negotiations over the next budget.
A group of hard-line conservatives in the Republican Party is demanding strict new controls on government spending that are opposed by President Barack Obama's Democratic Party allies in Congress.
The tense negotiations were complicated by the abrupt resignation of House Speaker John Boehner, who announced plans to leave Congress at the end of October. There is no apparent agreement on who would replace him. That leaves the fractious House of Representatives without leadership for the time being.