The United States imposed 50% tariffs on $20 billion worth of Canadian products early Saturday, and Canada said it would retaliate beginning Sept. 8 after last-ditch negotiations failed to resolve the latest strain in relations.
The new levies were set to go into effect early Wednesday.
Ambassador Pete Hoekstra is accused of normalizing diplomatic attacks on Canada.
Canada on Friday celebrated the completion of a new bridge to the U.S. over the Detroit River, cutting a ceremonial ribbon on a multibillion-dollar, multiyear project that will serve as a critical path for trade, jobs and tourism between the countries.
The tariffs will take effect 30 days from now.