The doubling of levies, in response to the Canadian province of Ontario placing a 25% tariff on electricity coming into the U.S., take effect from Wednesday.
Consumers buying aluminum on the physical market typically pay the London Metal Exchange (LME) benchmark aluminum price plus a premium that covers taxes, transport and handling costs.
Traders predict premiums will continue to rise as producers pass on as much of the extra costs of tariffs as they can.
Canadian smelters account for most primary and alloyed aluminum shipped to the United States. Aluminum is vital for the transport, packaging and construction industries.
About 70%, or 3.92 million metric tons of the primary and alloyed aluminum exported to the United States last year, came from Canada, according to information provider Trade Data Monitor (TDM).
The 25% tariff originally planned would have meant the premium would have had to rise to 47 cents a lb or more than $1,000 a ton to cover the extra costs for sellers, analysts have calculated.
The U.S. Midwest duty-paid aluminum premium jumped to 45 U.S. cents per lb, or more than $990 a metric ton, on Tuesday, a jump of nearly 20% from Monday. It has climbed more than 70% since the start of 2025 .
During his previous presidency, Trump in 2018 sought to use tariffs on aluminum to encourage investment in capacity.
Given that aluminum smelters take longer to build than political election cycles, analysts were sceptical investors would be confident to spend the large capital sums needed.
“U.S. primary aluminum production has experienced a sequential decline over the past two decades due to often thin or negative margins, and the implementation of tariffs in 2018 has not sustainably helped local supply to recover,” Macquarie analysts said in a note last month.
While premiums for U.S. buyers have risen, industry sources have said they are likely to continue falling elsewhere as aluminum produced in countries where import levies apply are diverted.
In Europe, the duty-paid physical market premium has dropped to $240 a metric ton, the lowest since January last year. It has fallen more than 35% since the start of 2025.
