New 50% U.S. tariffs on Canadian goods spare energy, potash and critical minerals

On July 20, 2026 the President signed three proclamations under Section 338 of the Tariff Act of 1930, a provision aimed at countries found to discriminate against U.S. commerce, imposing an additional 50% ad valorem duty on specified Canadian products. The motor-vehicles proclamation sets the effective time at 12:01 a.m. eastern on August 19, 2026, excludes articles already subject to Section 232 duties and civil aircraft, and leaves the detailed product list to annexes [1].

The annexes are where the mining sector lives. Blakes, a Canadian law firm, reads them as excluding energy, potash, fish and critical minerals, while noting that, unlike earlier U.S. measures, the duties apply even to goods that qualify under CUSMA, the U.S.–Mexico–Canada trade agreement; Blakes gives an August 22 effective date against the proclamation's August 19 [2]. "Critical minerals" is not defined in the proclamation text we read, and the natural reference is the U.S. Geological Survey's 2025 list of 60, which added copper, potash, silver and uranium in November 2025 [3].

For a U.S. investor in Canadian resources the carve-out is the whole story. Uranium and potash keep crossing the border without the surcharge, which protects the revenue line of the producers this publication covers. The same office that wrote the annex can rewrite it, so the exemption is a policy fact with a date, not a permanent feature of the trade.