Mnuchin Says Tax Overhaul Plan Will Still Happen by Year's End

"There are certain things we like" about the border-adjusted tax, but "there are certain things we don't," Mnuchin said. He cited concern over currency adjustments that underpin the proposal. Proponents of the tax say the U.S. dollar would rise 25 percent to offset the higher price of imported goods.

"If the currency does correct in a much stronger currency, then that hurts our exports, if the currency doesn't correct we have price appreciation and inflation particularly in consumer goods, then that's a concern," he said. "We're working with the House and having discussions on the specifics of it."

Mnuchin said the administration's tax priorities are to simplify personal taxes, create middle-class tax cuts and make business taxes competitive. He also said the White House's tax overhaul plan wouldn't increase the federal deficit.

"Some of the lowering of rates is going to be offset" by fewer deductions and 'simpler' taxes, he said. "But the majority will fundamentally come from growth and dynamic scoring." Dynamic scoring refers to complex economic models that take into account the impact of tax policies on economic growth and consumer well-being.

Both Trump's campaign plan and the House Republican proposal would collapse the existing seven existing income tax brackets into three, with a top rate of 33 percent. Mnuchin said Thursday that administration officials are looking at whether there should be four brackets instead of three.

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