The American Gem Trade Association (AGTA) has alerted members that US President Donald Trump has announced three proclamations imposing 50% tariffs on nearly US$20 billion-worth of Canadian goods imported into the United States.

The tariffs, issued under Section 338 of the Tariff Act of 1930, are scheduled to take effect on 19 August 2026, following a 30-day implementation period. Unlike the ongoing Section 301 investigations, Section 338 is a rarely invoked provision that allows the President to impose duties without lengthy investigations.

According to the US Trade Representative, the measures are based on a presidential determination that Canada maintains discriminatory trade practices that burden US commerce. The proclamations specifically cite Canada’s policies on automobile trade, dairy protections, and alcohol sales.

The tariffs cover a broad range of Canadian imports. They will apply regardless of whether goods qualify for preferential treatment under the United States–Mexico–Canada Agreement (USMCA) and will be levied in addition to any existing tariffs or fees.

AGTA noted that while the 30-day window provides an opportunity for bilateral negotiations, the proclamations include exemptions for certain categories, including energy and critical minerals. Although gemstones have not been specifically identified among the exempt products, the association said it is hopeful they will qualify under the critical minerals exemption.