USMCA Review Looms as Trump Threatens New Tariffs After Supreme Court Defeat

Washington D.C. – The upcoming review of the United States-Mexico-Canada Agreement (USMCA) is taking on heightened significance following a Supreme Court ruling that struck down tariffs imposed by former President Donald Trump, coupled with his subsequent vow to implement new trade restrictions. Experts suggest this confluence of events could lead to increased volatility and unpredictability in North American trade relations.

Supreme Court Ruling and Trump’s Response

On February 20, 2026, the U.S. Supreme Court ruled against Trump’s sweeping tariffs, which were authorized under the International Emergency Economic Powers Act (IEEPA). The court found that the former president had exceeded his authority in unilaterally imposing these duties. Trump responded by announcing a new 10% global tariff under Section 122, addressing imbalances in payments, though this tariff is temporary and requires Congressional approval to extend beyond 150 days. He also indicated he would explore other avenues for imposing trade restrictions.

Impact on the USMCA Review

The USMCA review, scheduled for July, requires Canada, Mexico, and the United States to agree to maintain the trade deal originally negotiated during Trump’s first term. Currently, most goods traded between the three countries flow duty-free if they meet USMCA compliance standards. However, experts believe Trump’s frustration over the Supreme Court decision could make him more aggressive during the negotiations.

“The main implication for the USMCA negotiations is that President Trump is now more frustrated and more in need of a ‘win,’” said Robert Embree, vice president and senior economist at Rosenberg Research & Associates, according to Platts. “He’s more determined than ever to prove that tariffs are good policy. This makes him more likely to use new, unpredictable threats of tariffs as we approach the summer USMCA renewal deadline.”

Potential Tariff Tools and Leverage

Experts are monitoring for potential use of other legal authorities, including national security tariffs (Section 232), tariffs responding to unfair trade practices (Section 301), and the newly invoked Section 122. These remedies require more thorough justification than the IEEPA-based tariffs struck down by the court.

Barry Appleton, a managing partner at Appleton & Associates International Lawyers, suggested the ruling hasn’t eliminated Trump’s leverage, but rather shifted the tools available. Bloomberg reported Appleton stating, “We’re going to see weaponizations of a variety of different tools that were never, ever conceived of in that way, utilized in that fashion, because the president does not want to go to Congress.”

Canada and Mexico’s Positions

While the Supreme Court ruling may offer some temporary leverage to Canada and Mexico, its impact is considered modest. Canada accounted for approximately 70% of U.S. Imports of primary aluminum in 2024, and, along with Mexico, represented 93% of total U.S. Steel exports in 2024. The exemption for USMCA-compliant products previously gave Canada and Mexico an advantage over countries facing higher duties under IEEPA.

Mexico is adopting a wait-and-see approach, with Economy Minister Marcelo Ebrard stating the country will assess the impact of any new measures before responding. Canada and the US governments have not yet issued public comments on the situation.

Looking Ahead

The USMCA review is poised to be a critical juncture in North American trade relations. The Supreme Court’s decision and Trump’s reaction have injected a new layer of uncertainty into the process. The coming months will be crucial in determining whether the three countries can reaffirm their commitment to the USMCA or if new trade disputes will emerge.