US-Canada trade war: A timeline of tariffs and retaliation

The United States and Canada, long-standing economic partners, are locked in a deepening trade conflict. President Donald Trump's second term has been marked by a barrage of tariffs and threats, straining the relationship and creating uncertainty for businesses and consumers on both sides of the border.

The friction began early, with Trump announcing plans for 25% tariffs on Canadian imports on his first day back in office. He soon signed an executive order to implement them, citing a national emergency over undocumented immigration and drug trafficking. Outgoing Canadian Prime Minister Justin Trudeau promised retaliatory levies.

After a brief pause, limited tariffs took effect in March 2025. The US later exempted automakers and goods compliant with the US-Mexico-Canada Agreement (USMCA). However, new 25% tariffs on steel and aluminum went into effect globally, prompting Canada to impose its own tariffs on US imports.

In April, Trump announced sweeping "reciprocal" tariffs on nearly all trading partners, though no additional levies were placed on Canada at that time. The legal basis for these tariffs was challenged, with a US court initially ruling Trump overstepped his authority before an appeals court temporarily halted that decision.

Sectoral tariffs continued to pile up. A 25% tariff on auto imports began in April, and Canada responded with matching tariffs on non-USMCA compliant vehicles. By June, the US had increased tariffs on steel and aluminum to 50%, with Canada threatening similar measures.

Tensions escalated further in August when the US imposed a 35% tariff on a range of Canadian goods and a 50% levy on imported copper. Canada later dropped many of its retaliatory tariffs to match US exemptions for USMCA-covered goods, a move critics called capitulation.

In late October, Canada outlined plans to diversify its exports away from the US. Trump, angered by a Canadian television ad opposing US tariffs, pulled the plug on trade talks. The ad was later withdrawn to resume negotiations.

The legal fight over the emergency tariffs reached the Supreme Court, which struck them down in February. Trump quickly enacted a temporary 10% global levy using a different law.

Relations soured further in January when Canada moved to mend ties with China, cutting tariffs on Chinese EVs. Trump threatened a 100% tariff on Canadian goods if a broader deal was pursued, a threat that went unrealized.

Negotiations to renew the USMCA began in March, with Canada calling for a 16-year extension. The US was not ready to agree, leaving the pact in effect until 2036.

In July, Trump threatened 50% tariffs on many Canadian goods, including those previously protected under the USMCA, citing unfair discrimination against US automobiles, alcohol, and dairy. After a brief delay, these tariffs took effect on August 22, covering about 5% of Canada's annual exports to the US, from hockey sticks to tongue depressors. Prime Minister Mark Carney promised to match them "dollar for dollar," with retaliatory tariffs set for September 8.