As a share of gross domestic product, the national debt is forecast to swell to 96.2 percent from 78 percent over the next 10 years —the highest mark since 1946 and well more than twice the average over the past five decades, the CBO said in April.
Cohn, who quit the White House post earlier this year after 15 months as director of the National Economic Council, said his conviction on the topic comes from the way Trump crafts his economic philosophy.
"The president looks at these economic decisions in a very simple lens: 'I want to grow the U.S. economy, I want to create jobs, I want to create wage growth,'" the former Goldman Sachs executive said of Trump.
"If the federal government can do something that helps [him] accomplish those three things, he will be 100 percent inclined to do it," Cohn added. "I mean, that's literally how he looks at it."
Once the chief operating officer and president of Goldman, Cohn's time in the administration oversaw a historic overhaul of the U.S. tax code that resulted in the reduction of the corporate tax rate to 21 percent.
But despite agreements on deregulation and tax cuts, Cohn and Trump frequently sparred over the president's plans to impose trade sanctions on economic allies.
For his part, Cohn said he would have preferred a public-private partnership to tackle infrastructure, but his plan faced fierce opposition on Capitol Hill.
By combining "a little bit" of U.S. equity and letting the private sector leverage it, Cohn said the venture could then sell off a lot of the noncrucial infrastructure back to the government.