U.S. President Donald Trump's executive order hitting Canada and Mexico with 25 per cent across-the-board tariffs, with a lower 10 per cent levy on Canadian energy, took effect at 12:01 a.m. ET on Tuesday.
Canada has responded with retaliatory tariffs, and markets are falling as investors brace for the economic impact that the duties will have on economies on both sides of the border.
Canadians confused about Trump's plans aren't alone, with the U.S. president at times contradicting himself about his own tariff plans.
Here's what has happened so far, and some key dates coming up as Canada is officially in a trade war with its biggest trading partner.
March 4
Trump initially signed an order on Feb. 1 imposing blanket tariffs of 25 per cent on virtually all goods entering the U.S. from Canada and Mexico, and a reduced 10 per cent tariff on energy exports, set to begin on Feb. 4.
But a few days later on Feb. 3, he "paused" the implementation of those tariffs for 30 days as Canada pledged action to secure the border.
Trump's Feb. 1 order also imposed 10 per cent tariffs on goods entering the U.S. from China, which have gone ahead.
There were hopes that the border security measures Canada took during the month-long pause could stave off the tariffs, but on March 3 Trump confirmed they would go ahead, which they did.
Prime Minister Justin Trudeau announced broad retaliatory tariffs Tuesday on U.S. goods including food, alcohol, furniture, paper and more.
March 12
Trump followed up his initial tariff orders with a new salvo launched against steel and aluminum exporters.
On Feb. 10, he signed a plan to institute 25 per cent tariffs on all steel and aluminum entering the U.S., ending previous exemptions for Canada.
Those tariffs would take effect on March 12.
The new taxes on steel and aluminum would stack on top of the existing tariffs.
That would bring the effective import tax on Canadian steel and aluminum to 50 per cent as of March 12.
April 1
On Trump's first day in office, he signed an executive order to enact the "America First Trade Policy."
That order called for his trade and commerce officials to report back to him by April 1 on a sweeping review of U.S. trade policy and relationships.
That date does not come with an imposition of any tariffs by default, but does direct Trump's administration to begin examining the Canada-U.S.-Mexico Agreement, which Trump signed in 2018, ahead of a planned 2026 review.
April 2
In a Feb. 27 Truth Social post, Trump said that April 2 would mark the start of "reciprocal" tariffs, which would apply to goods coming in from countries that have tariffs on U.S. goods.
These would be on top of other tariffs and would match the rates charged by other countries, including subsidies and value-added taxes.
Trump has given little indication on the scope these reciprocal tariffs would take, but he signed a memorandum on Feb. 13 directing his trade czar to examine what he perceives as unfair trade practices from other nations.
A fact sheet accompanying that memorandum flagged Canada's digital services tax targeting tech giants doing business in the country as one such measure the U.S. might like to see addressed with reciprocal tariffs.
Trump has also threatened to levy tariffs on imported automobiles coming into the U.S.
He said on Feb. 14 that those tariffs could come "around April 2," adding the following week that the levies would be "in the neighbourhood of 25 per cent."
Around the same time, he floated imposing similar tariffs on pharmaceuticals and semiconductors, but has yet to provide a timeline for those.
