"I am not anti-trade. I am pro-trade," Ross declared to the committee. "But I'm pro-sensible trade. [Being anti-trade] is a disadvantage of the American worker and the American manufacturing community."
Ross added that he believes the Trump administration "should provide access to our markets to those countries who play fair, play by the rules and give everybody a fair chance to compete."
"Those who do not should not get away with it," he added. "They should be punished and severely."
Ross, who says he favors bilateral trade agreements rather than multilateral pacts, was briefly interrupted by two protestors who were quickly escorted out of the room after they shouted about the Trans-Pacific Partnership (TPP).
Ross said he was initially in favor of the 12-country trade agreement that has stalled in the face of bipartisan opposition on Capitol Hill. But once he delved into the details, he said he discovered elements that were "not consistent with what was advertised."
"I think we cannot afford trade that is inherently bad for American workers and for American businesses ... and I think the number one objective would be expanding our exports," Ross testified. "I think that there many things we can do that we haven't been doing."
Ross revealed that he terminated a household employee who could not reproduce documentation showing the employee was in the country legally. The worker had initially provided a driver's license and Social Security card in 2009, but was unable to provide such documentation again and was fired within the past month as Ross prepared for his confirmation hearing.
"We did the best that we thought we could do in order to verify the legality of the employment and it turned out that was incorrect," Ross said, adding that it was just one employee among a dozen who had failed to provide the documentation. Members of the committee seemed satisfied with Ross' explanation and his handling of the former employee.
Although Ross has divested more than 90 percent of his holdings and resigned from 50 corporate boards in advance of his confirmation, he refused to criticize Trump for not taking similar steps to avoid a conflict of interest.
"I'm not familiar enough senator with the exactitude of his holdings to have any judgment as to how easy or hard it would be to do it," he said.
Ross told the committee that he agrees with Trump on the necessity to renegotiate the North American Free Trade Agreement, known as NAFTA, calling it "logically the first thing for us to deal with."
"We ought to solidify relationships in the best way we can in our own territory before we go off to other jurisdictions," Ross said. "So I think that should be and hopefully will be if I'm confirmed a very very early topic in this administration."
Committee members largely focused their questions on his policy proposals, as well as the policies of Trump on climate change, spectrum, infrastructure and trade. The hearing lasted just under four hours.
"I believe science is science and scientists should perform science," Ross said.
The Trump transition says Ross will be “instrumental” in implementing Trump’s America First economic plan, which aims to create more than 25 million jobs in the next decade.
“Together, we will take on the special interests and stand up for American jobs,” Trump noted in a news release tapping Ross for Commerce. “Wilbur knows that cutting taxes for working families, reducing burdensome government regulations and unleashing America's energy resources will strengthen our economy at a time when our country needs to see significant growth.”
As the owner of the Sago mine, Ross was accused of ignoring safety regulations that cost the lives of 12 miners in the 2006 disaster. Days after the mine explosion, Ross defended his company's management of the mine amid multiple warning signs in the form of previously-issued safety citations.
If confirmed, Ross would take over for Penny Pritzker, another billionaire, though loyal to President Obama.
ABC's Alex Mallin contributed to this report