Kirsten Hillman, Canada’s ambassador to the U.S., said Monday that 99 percent of products traded between the two nations are tariff-free, as tensions escalate following President Trump’s imposition of new tariffs and Ontario’s retaliatory measures.

Trump said he wanted to increase steel and aluminum tariffs by an additional 25 percent specifically on Canada, in addition to the already planned 25 percent tariffs slated to go into effect for all steel and aluminum imports,

Trump said the increase of the tariffs set to take effect on Wednesday is a response to the price increases by Ontario on electricity sold to the United States.