President-elect Donald Trump's nominee to head the U.S. Commerce Department says changing the free-trade agreement with Mexico and Canada tops his agenda. Billionaire investor Wilbur Ross Jr., speaking to the Senate Commerce Committee Wednesday, called China the "most protectionist" country of the world's large nations. He also said nations that do not trade fairly should be "severely punished." Ross told senators that he was not anti-trade, but favored "sensible" trade that benefited U.S. workers and companies. If he is confirmed by the Senate as commerce secretary, he would lead the Commerce Department's 47,000 employees in efforts to bolster the economy and support U.S. business. The department does that by forecasting the weather, gathering and analyzing economic data, taking the U.S. Census and performing many other tasks. Ross said he was probably the only prospective commerce secretary who once held a temporary job as a census taker, which left him with respect for the work of the agency. Ross, who has a close friendship with Trump, is expected to play an even larger role in trade issues than most other commerce secretaries. Committee Chairman John Thune, a South Dakota Republican, said Ross would bring "decades of business, entrepreneurial and civic experience" to the position. Supporters said Ross saved U.S. jobs in coal, steel and textile industries, while critics said the nominee also outsourced jobs to low-wage nations and laid off American workers. His hearing was briefly interrupted by protesters. He also has been criticized for the 2006 death of 12 workers at a coal mine he owned in West Virginia. The Sago coal mine had a history of numerous safety violations. Federal safety inspectors eventually cited the coal mine with 208 violations. Ross, 79, made a fortune buying up failing companies, improving their financial performance, and often selling them at a profit. He received degrees from Yale and Harvard universities but has little government experience.