Treasury Secretary Jacob Lew will testify at a Senate Finance Committee hearing on the debt ceiling on Thursday, a week before the Oct. 17 deadline when Congress must raise the statutory limit on borrowing authority or plunge the nation into default.

Lew spoke on multiple talk shows on Sunday, warning that if the U.S. defaults on its debt, the nation’s economy could see major negative impacts.

“This brinkmanship over and over again is bad for the economy,” Lew said on Fox News Sunday. “We’re the world leader. We’re the strongest, deepest economy in the world. Our currency is the world’s reserve currency.”

The Senate Finance Committee hearing will take place at 8:30 a.m. Thursday.