"The growth is going to pay for it," Trump told ABC News in the White House's Rose Garden during Take Our Daughters and Sons to Work Day, as he signed autographs for children of members of the media and administration officials. "Wait until you see the growth."
The blueprint was unveiled Wednesday as a one-page document -- which outlined a plan that would slice the corporate tax rate to 15 percent while simplifying the individual tax code -- but it gave few details on what the plan would mean for the federal deficit and national debt.
"It will happen quickly, and ... the jobs have already started," Trump said, adding that "a lot of positive things" are going to happen on tax reform. "You saw last year, GDP at 1.6 percent. That is a terrible situation for this country but last year is not this year."
But experts interviewed this week by ABC News said economic growth likely wouldn't make up for the massive loss in federal revenue. One analysis, by the bipartisan Committee for a Responsible Federal Budget estimates the Trump’s plan could cost anywhere between 3 and 7 trillion dollars in lost revenue over the next decade.
Treasury Secretary Steve Mnuchin made similar comments yesterday at the White House. "This will pay for itself with growth and with reduction of different deductions and closing loopholes," he said.
ABC News' Lauren Pearle and Zunaira Zaki contributed to this report.