President-elect Donald Trump's tax cut proposals will help the middle class, not the upper class, according to Steven Mnuchin, Trump's choice to lead the Treasury Department.

Mnuchin, who was the Trump campaign's national finance chairman, made the comments during an interview on CNBC's "Squawk Box."

"Any reductions we have in upper-income taxes will be offset by less deductions so that there will be no absolute tax cut for the upper class."

Some deductions would still be available, such as charitable donation. Mortgage interest will be capped, but "some deductibility" will be available, Mnuchin said.

The middle class would not pay more under Trump's tax plan, and the details would be made apparent.

"When we work with Congress and we go through this, it will be very clear. This is a middle-income tax cut. And the child care credit is a big aspect of this," he added.

Mnuchin said he and Trump's pick for secretary of commerce, Wilbur Ross, were already working on an "integrated approach" for the plan.

The former Goldman Sachs banker is also a movie producer. The Washington Post reported that he is listed as a producer on the "X-Men" films as well as "Avatar."

Democratic Sen. Elizabeth Warren weighed in on Mnuchin, calling him the "Forrest Gump of the financial crisis — he managed to participate in all the worst practices of Wall Street."

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