The proposed Section 232 expansion would mostly fall on USMCA imports

KUALA LUMPUR, 13 AUGUST 2026 —

**U.S. Proposes Tariff Expansion on Steel, Aluminium and Copper Imports; Mexico and Canada Most Exposed**

WASHINGTON, Aug 13 — The U.S. Commerce Department’s Bureau of Industry and Security (BIS) has proposed expanding the Section 232 tariff programme to cover 14 additional steel, aluminium and copper-related articles, with imports under these categories valued at $13.0 billion in 2025. The proposal, which includes duties ranging from 15% to 50%, would primarily affect imports from Mexico and Canada, which together account for 41.6% of the trade in question.

Public comments are open until August 27, 2026, though the move does not require formal notice-and-comment procedures under the Administrative Procedure Act.

The proposed expansion targets 14 tariff lines, with measurable imports (excluding filled containers) totaling $9.6 billion in 2025—an increase of 13.4% from 2024. Of this, approximately $9.0 billion represents trade not already subject to Section 232 duties. The largest categories include linear-acting hydraulic power engines and motors ($3.7 billion) and electric conductor cables ($3.2 billion), which together make up over 70% of the measurable trade.

Imports in the first five months of 2026 reached $5.7 billion, though this figure is not annualised.

Mexico and Canada dominate supply chains in five of the 13 measurable articles, including tanker trailers (99.8%), agricultural trailers (98.3%), fire extinguishers (79.7%), other trailers (76.6%) and electric conductor cables (55.8%). China, meanwhile, is the largest single supplier for brass-wind instruments (36.9%), floor safes (36.3%) and heat exchange unit parts (22.2%), though it holds no majority share in any category.

Across all measurable articles, North American suppliers accounted for $4.0 billion of 2025 imports, while China contributed $1.0 billion.

The proposed duties vary by product: 25% on ten articles, 15% on agricultural trailers and 50% on filled steel containers, with the latter duty applied to the container’s value rather than its contents. Two crane articles would follow the rates set in a June 2026 proclamation on mobile industrial equipment. No duties are currently in force, and any expansion requires joint approval from the Commerce Department and the U.S. Trade Representative.

The proposal follows recent adjustments to Section 232, which removed 144 product lines from scope in April 2026 under Proclamation 11021. Six of the 14 proposed articles have prior Section 232 coverage, including welding-machine parts (since March 2025) and certain insulated cables (since August 2025). Fire extinguishers and filled containers were previously covered as steel derivatives but were removed in April 2026; the notice proposes reinstating them without referencing their prior inclusion.

Existing duties further complicate the landscape. Chinese-origin imports of most articles have faced Section 301 tariffs of 25% since 2018–19, with additional forced-labour duties of 10–12.5% introduced in July 2026. These forced-labour duties exempt Section 232-covered goods and duty-free USMCA entries from Canada and Mexico, though non-qualifying North American goods pay 10%.

A separate Section 338 action imposes a 50% duty on Canadian floor safes, one cable line and one crane line starting August 19, 2026, but exempts Section 232-covered products.

For North American trade under USMCA, inclusion in Section 232 would shift imports from no additional duty to rates of 15–50%, depending on the article. For most other origins, including China, the change would replace existing forced-labour duties with higher Section 232 rates—a smaller adjustment than the headline figures suggest. On the three Canadian lines under Section 338, designation would reduce duties from 50% to lower Section 232 rates.

The BIS seeks public feedback on five key points: metal intensity of the products, threats to national security from import volumes, domestic production capacity, economic impacts and other relevant factors. While the comment period is not legally required, the agency invites input to inform its decision-making process. Commerce and the USTR will jointly determine whether to include any of the 14 articles, with no set timeline for a final decision.

The proposal underscores the Biden administration’s ongoing use of Section 232 to address national security concerns in strategic industries, while highlighting the disproportionate exposure of North American supply chains to potential tariff expansions. The outcome could reshape trade flows in steel, aluminium and copper-related goods, with ripple effects across regional manufacturing and supply networks.