Trump picks for Treasury and Commerce want to boost economy through tax and trade reform

Treasury secretary pick Steve Mnuchin: We can sustain 3-4% economic growth

President-elect Donald Trump's pick for Treasury secretary told CNBC on Wednesday that the most important action item for the incoming administration is to boost the economy.

Steven Mnuchin made his comments on "Squawk Box," as his selection was being announced. He said he believes the U.S. economy can grow at a sustained rate of 3 percent to 4 percent.

Fair trade will also help boost the economy, Mnuchin said — sentiments echoed on CNBC by Trump's choice for Commerce secretary, Wilbur Ross.

Mnuchin said tax reform is going to be a major driver of that growth, and added that the Trump administration is going to bring a lot of money back into the U.S. by cutting the corporate rate to 15 percent.

Ross said he aims to fix "dumb trade" deals, while getting rid of tariff barriers.

The Dodd-Frank banking regulations are too complicated and a headwind to lending, said Mnuchin, a key Trump campaign figure and a Wall Street veteran with ties to Hollywood.

Mnuchin said interest rates are likely to stay low for a few years, but the recent rise in bond yields make sense. "We'll look at potentially extending maturity of the debt because eventually we're going to have higher interest rates."

Federal Reserve Chair Janet Yellen has done a good job, said Mnuchin.

Ross, a billionaire investor in distressed assets, said he thinks Yellen has done a "reasonably good job" under tough circumstances.

Mnuchin began his career at Goldman Sachs; then worked for his Yale roommate, hedge fund manager Eddie Lampert and later George Soros, the investor and benefactor to liberal issues who backed Mnuchin's start of Dune Capital Management.

In 2009, Dune Capital bought bankrupt housing leader IndyMac, and rebuilt it as OneWest, which was sold in 2015 for a big profit.

Mnuchin, 53, also financed many Hollywood hits, with producer credits in the past year for "Sully," "Storks," "The Legend of Tarzan" and "Batman v Superman: Dawn of Justice."

Ross, 79, also was an advisor to Trump during the campaign.

He has made what's estimated by Forbes to be a $2.9 billion fortune by saving companies in a variety of sectors, including steel and coal.

Before starting WL Ross & Co, Ross led Rothschild's bankruptcy practice for 25 years.

— Reuters contributed to this report.