Mexico and Canada were happy to hear about President’s Trump’s willingness to exclude them from tariffs on steel and 
aluminum exports to the U.S. However, they expect any talks about a possible permanent exemption to take place outside of the North American Free Trade Agreement negotiations.
Politico quotes the Mexican Economy Ministry in a release that says, “The process of negotiations for the NAFTA modernization continues on a course independent of this or any other internal political measure that the U.S. government takes.” Also, Canada “won’t rest until the prospect of these duties is fully and permanently lifted,” Cynthia Freeland told reporters in Toronto. She also says the tariff discussions and NAFTA negotiations are completely different, adding that, “We treat them on totally separate tracks.”
However, Trump more directly tied Canada and Mexico’s exclusion from the tariffs to a successful NAFTA outcome. “We’re going to hold off the tariff on these two countries to see whether or not we can make a successful deal on NAFTA,” he said during a signing ceremony for the two proclamations that will impose the 25 percent tariff on steel imports and 10 percent tariff on aluminum. “National security is a very important aspect of this deal, and if we’re making the deal on NAFTA, this will figure into whether or not there are tariffs on Canada and Mexico,” says the president.
From the National Association of Farm Broadcasting News Service.