Congress has "no other choice" but to increase the nation's borrowing limit because it's money that's already been agreed upon and spent, said Gary Cohn, director of President Donald Trump's National Economic Council.

"I'm confident that Congress will get the ceiling raised," he told CNBC's "Squawk on the Street," on Friday, addressing what's become a yearly will-they-wo n't -they discussion as conservatives threaten to default on the federal debt to try to rein in government spending.

"At the end of the day, the deficit ceiling has to be raised. This is money that the Congress appropriated. They chose to spend the money," said Cohn, formerly second in command at Goldman Sachs.

Treasury Secretary Steven Mnuchin, also a Goldman alum, has said the debit ceiling needs to be increased by August so the government can keep paying its bills. Mnuchin told lawmakers last week he would prefer a clean hike of the borrowing limit, without attaching any spending cuts.

But on Wednesday, in the good-cop-bad-cop routine, White House Office of Management and Budget Director Mick Mulvaney told the Washington Examiner he'd like to see measures that drive "certain spending reforms and debt reforms in the future."

Cohn told CNBC on Friday that Treasury secretaries all want a clean debt limit hike. But he said the Trump administration is prepared to accept riders if that's what it takes to get the ceiling increased.

"In a perfect world you would love to have a clean debt ceiling," Cohn added. "But if we need to get things attached to get it through, we'll attach things."