The Aluminium Association of Canada (AAC) has condemned the US’ decision to impose a 50% tariff on Canadian aluminium, warning that the move could destabilise the North American supply chain and push manufacturers toward less secure, higher-carbon sources of supply.

On Tuesday, US President Donald Trump signed a order doubling tariffs on steel and aluminium imports from 25% to 50%. The measures, which came into effect on Wednesday, were intended to secure the future of the US industry.

“A 50% tariff on Canadian aluminium will suppress demand across the continent – whether the metal is produced in Canada or the US,” said AAC president and CEO Jean Simard. “It will impact workers on both sides of the border and disrupt key sectors including defense, construction and automotive.”

The new tariff rate of $1 349.50/t renders Canadian exports to the US economically unviable, the AAC said, threatening the longstanding integrated industrial base between the two countries. While Canadian producers remain committed to US customers, the industry is now considering redirecting trade flows to the European Union.

“This measure risks increasing US reliance on aluminium from distant sources – including China, Russia, India and the Middle East – for a material critical to national security,” Simard said. “It jeopardises 125 years of cross-border industrial cooperation and will trigger a fundamental shift in global trade flows.”

The Canadian industry supports the US goal to boost its domestic aluminium output from 50% to 80% of consumption, but warned that tariffs are the wrong approach. According to the AAC, long-term capital investment in aluminium smelting requires policy certainty – not protectionist measures. Even with higher domestic output, the US will remain a net importer of aluminium.

Each year, Canada ships about 2.7-million tonnes of aluminium to the US, representing a considerable embedded energy benefit: equivalent to 40-million megawatt-hours or enough to power four Hoover Dams. The aluminium is produced using hydroelectric power, giving it a low carbon footprint.

Canada’s aluminium sector employs 9 500 workers and supplies material that supports over 700 000 US manufacturing jobs. The binational value chain contributes more than $228-billion a year to the US economy.

The AAC urged the US to focus instead on addressing overcapacity and unfair trade practices from China. “Canadian aluminium is not – and will not be – a backdoor for unfair trade,” the association stated, pointing to Canada’s implementation of aluminium traceability systems and anti-circumvention rules.

The group argued that exempting Canadian aluminium from the new tariffs is essential to safeguarding economic and national security interests on both sides of the border. With the US consuming five times more aluminium than it produces, the AAC warned that added tariffs will only drive up prices for manufacturers and consumers amid persistent inflation concerns.