Hours before the 25 percent tariff on cars made in Canada went into effect, the largest auto plant in Windsor, Ontario, announced it would close for two weeks.

The 25% counter-tariffsCanada said last week it would impose on some U.S.-made vehicles will go into effect on April 9, the federal finance ministry said on Tuesday.

The White House says President Trump's trade policy will come to a head on April 2, when the administration unveils a plan for reciprocal tariffs. Why it matters: The new tariff regime will take aim at trading partners that officials believe treat domestic exporters unfairly.