Source: Supply Chain Dive
Date: 9th September 2026 

New U.S. measures will prohibit imports of selected Canadian goods from September 29, marking a further escalation in cross-border trade restrictions as Canada’s retaliatory tariffs take effect.

Trade tensions between the United States and Canada have escalated further, with the U.S. introducing new import restrictions alongside an expansion of its 50% tariffs on selected Canadian products.

The latest measures come as Canada begins implementing its own retaliatory tariffs of 15%, 25% and 50% on $27.6 billion of U.S. imports, effective September 8. Canada’s measures cover sectors including steel and aluminum, dairy, appliances, agricultural equipment, pulp and paper, plastics and electronics.

The developments increase the complexity facing companies operating across one of the world’s most integrated cross-border supply chains.

U.S. expands 50% tariffs. From September 15, the U.S. will modify and expand the range of Canadian products subject to additional 50% duties.

The measures cover selected products across sectors including food, metals, materials and manufactured goods. Importantly, some of the additional duties can apply alongside existing tariffs, depending on the product classification and applicable trade measure.

The latest changes build on U.S. measures introduced earlier this year that imposed additional 50% tariffs on selected Canadian imports.

For importers, this makes accurate HS classification and tariff assessment increasingly important as the treatment of individual products continues to change.

From higher tariffs to import restrictions. The more significant development is the move beyond tariffs.

From September 29, the U.S. plans to prohibit imports of selected Canadian products in targeted categories, including certain alcoholic beverages, dairy-related goods and motor vehicles.

Until the restrictions take effect, covered goods remain subject to the applicable additional duties.

This represents an important change for supply chains. A tariff increases the landed cost of a shipment but may still allow trade to continue. An import prohibition can prevent the affected product from entering the market altogether, requiring businesses to reconsider sourcing, purchase orders, inventory, and transportation arrangements.

Canada implements countermeasures. Canada’s counter-tariffs took effect on September 8, with rates designed to match corresponding U.S. measures.

Certain steel and aluminum products have seen existing Canadian counter-tariffs increase from 25% to 50%, while other existing measures, including those covering U.S. automobiles, remain in place.

Canada has also confirmed an important provision for cargo already moving through the supply chain: qualifying U.S. goods already in transit to Canada when the new measures took effect are exempt from the latest counter-tariffs.

What This Means

• Companies trading between the U.S. and Canada should review affected products carefully against the latest tariff classifications and implementation dates.
• Pay particular attention to goods already ordered or in transit, customs classification, landed costs, and products facing upcoming import restrictions.
• Businesses directly affected may also need to reassess sourcing strategies, inventory positioning and alternative suppliers as the trade environment evolves.

The latest measures show how quickly a tariff dispute can become a broader customs and supply-chain challenge.

For businesses operating across the U.S.–Canada border, the priority is no longer simply calculating additional duty. Companies increasingly need to understand whether a product is affected, when the measure becomes effective and whether the goods remain eligible for importation at all.

As measures continue to evolve, close coordination between suppliers, importers, customs specialists and logistics providers will be essential to minimise unexpected costs and disruption to cross-border cargo flows.