If the U.S. doesn't secure substantive changes to the North American Free Trade Agreement, President Trump will make every effort to withdraw the country from the 23-year-old treaty, U.S. Commerce Secretary Wilbur Ross said on Wednesday, Oct. 25.

"The president is not a bluffer," Ross said a New York conference hosted by the Paley Center for Media. "Everyone would like to have an agreement, but we need a proper agreement. No agreement is better than a bad agreement."

As a Republican presidential candidate, Trump said he would scrap NAFTA unless Canada and Mexico agreed to make concessions. The three countries have met four times this year to discuss the treaty, with Mexican officials recently warning that if the U.S. walked away from NAFTA, Mexico would deepen trade ties with other countries.

Ross, 79, said that discussions with Canada and Mexico "are just now getting to the really hard issues." He said he expected talks to conclude in March, giving the president and Congress time to fashion legislation before the time limit for "fast track" authorization lapses in July. 

Trump's eagerness to make changes in NAFTA hasn't been well received by the Chamber of Commerce, the powerful business lobby that earlier this week flooded Capitol Hill with lobbyists urging legislators to tread lightly on the agreement. Ross, a billionaire investor who made his fortune through a series of distressed deals, brushed off criticism from the Chamber of Commerce as one of many groups with interest in the renegotiation process.

"NAFTA hasn't been so bad for corporate America, but it hasn't been so good for Mr. and Mrs America," Ross said. "We're trying to defend American workers in this; those are the people whom the president has made promises."

Ross said that U.S. corporations have had few qualms about moving factories and other operations to Guadalajara and other Mexican cities, but that it's not as easy for U.S. workers to relocate there. Corporations, he said, would do well to prepare for the possibility that there are going to be changes to the treaty. 

"Big businesses, naturally, don't want to deal with anything that causes increased expenditures or changes in their plans -- they're more or less happy with the way things are," he said. "We have respect for that, but we do think there are some imperfections in NAFTA that we think need to be fixed so that we don't have the continued migration of jobs."