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.

But there is no mention of wildfires in the executive orders that Trump signed on Monday.

Instead, the three proclamations list US trade irritants that were previously known to Canada related to cars, dairy and alcohol – signalling a breakdown of trade negotiations between the two countries.

On cars, Trump is accusing Canada of charging a tax on US motor vehicles and parts that are not covered under the existing free trade agreement between Canada, the US and Mexico, known as the USMCA.

He argues it is “unreasonable” and that Canada has discriminated against the US by not charging other countries a similar tax.

Automotive manufacturing in North America is highly integrated between Canada, the US and Mexico.

But Trump’s Commerce Secretary Howard Lutnick has said in the past that he believes Canada should “come second” to the US.

Trump has also named cars in the past as one issue where the two countries have competing interests.

Dairy, meanwhile, has long been a problem for the US, specifically Canada’s supply management system, which sets limits on foreign imports. Those that exceed the limit are charged a tariff upwards of 300%.

And lastly, the enduring boycott of US booze by most Canadian provinces has become a major sore point for the Americans since it was imposed last year.

Canadian premiers have said repeatedly that the boycott will be lifted if the US removes its tariffs on key Canadian sectors, including metals and automobiles.

Canadian trade negotiators have been working on trying to secure a deal that would at least reduce some of the current US tariffs.

The levies announced on Monday are a signal that the talks are going in the wrong direction for Canada.