U.S. Treasury Secretary Steven Mnuchin said he wants to see 'very significant' tax reform passed this year.

'We want to get this done by the August recess,' Mnuchin said this morning on CNBC, his first interview since taking office. 'We've been working closely with the leadership in the House and the Senate and we're looking at a combined plan.'

President Donald Trump's treasury secretary also repeated a promise that tax cuts would benefit the middle class and not, primarily, the rich.

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Treasury Secretary Steven Mnuchin told CNBC that the administration's priority was tax breaks for the middle class and simplifying the tax code for businesses

Treasury Secretary Steven Mnuchin, photographed Wednesday at the White House, said on CNBC this morning that he's aiming to have a tax reform bill passed by August recess

Mnuchin told the business network that the Trump administration is 'primarily focused on a middle income tax cut and a simplification for business.'

CNBC pointed out that most independent analyses of Trump's tax plan, which he floated during the campaign, would benefit the top tier of earners and not the middle class.

However, in November, Mnuchin told CNBC that he wanted 'no absolute tax cut for the upper class.'

Democratic Sen. Ron Wyden of Oregon has since nicknamed this stance the 'Mnuchin rule.'

Today, the new treasury secretary explained that if the rich were to get a tax cut, other loopholes that currently benefit the wealthy would be closed.

But he also didn't state as decidedly that top earners would not get an 'absolute' tax cut.

'Look, as I've said before, we're primarily focused on a middle-income tax cut and simplification for business,' he said.

'And what we are focused [on] is that on the high end, if there are tax cuts, that they are offset with reduction and deductions and other things,' he continued.

'So it's something we're going to carefully look at,' he added.

The Senate voted in favor of Mnuchin's nomination for the top treasury post last week.

Like several other members of Trump's team, he is a former Goldman Sachs banker and will serve as the president's point man on tax reform, financial deregulation and economic diplomacy efforts.