By Richard Rubin and Kate Davidson 

Senate Majority Leader Mitch McConnell (R., Ky.) said Monday there was "zero chance" that the U.S. would fail to raise the federal debt ceiling.

Mr. McConnell expressed confidence in Congress's ability to avoid missing federal payments in advance of a legislative sprint in September that will also address expiring government funding and several other pressing items.

"There is zero chance, no chance we won't raise the debt ceiling," he said at an event in his hometown, Louisville, Ky., with Treasury Secretary Steven Mnuchin.

Mr. Mnuchin said his "magic super Treasury powers" that allow the government to conserve cash and avoid issuing new debt will run out at the end of September.

If the debt ceiling isn't raised to allow new borrowing, the U.S. could default on its debt or miss payments of benefits and salaries.

"This is not about spending money," Mr. Mnuchin said. "This is about paying for what we've spent, and we cannot put the credit of the United States on the line."

What is still unclear is how the debt ceiling might get raised, while the bill will be a significant test for the Republican majorities in Congress and President Donald Trump.

Mr. Mnuchin reiterated his preference for a "clean" debt-limit increase without policy strings attached. But Republicans have for years insisted on conditions such as spending cuts.

In the Senate, a debt-limit bill will likely need to be bipartisan, because it would take 60 votes to overcome procedural hurdles.

Lawmakers return to Washington in September, after their August recess and the Labor Day holiday.

Write to Richard Rubin at richard.rubin@wsj.com and Kate Davidson at kate.davidson@wsj.com

(END) Dow Jones Newswires

August 21, 2017 14:07 ET (18:07 GMT)