US President Donald Trump has signed an order imposing a 50% tariff on a wide range of goods imported from Canada, in retaliation for what he called “unequal treatment” of US cars, dairy and alcohol.

The duties take effect on 19 August and mark a major escalation in trade tensions between the North American neighbours.

The White House said the tariffs were necessary to protect American businesses.

Goods targeted range from everyday consumer items like wine and hockey sticks to industrial goods such as commercial cement. However, several key exports will be spared, such as energy, potash, critical minerals and fish.

The new duties build on trade barriers already in place between the two nations.

The US has been maintaining active tariffs ranging from 15% to 50% on Canadian steel, aluminum, and copper. Washington also charges a 35% tariff on Canadian softwood lumber, alongside a 25% tax on non-US parts in cars.

Canada has its own 25% counter-tariff on selected imports of American steel, aluminium and vehicles.

Monday’s duties come in the wake of President Trump’s threat to impose tariffs over Canadian wildfire smoke drifting into US cities.