United States Prevailed in USMCA Dispute Against Mexico on Genetically Modified Corn

The USMCA panel presiding over the dispute issued its final report on December 20, 2024, which can be found here.

The United States initiated the dispute in August 2023, challenging two actions that Mexico implemented under a February 2023 decree regarding GM corn. First, the 2023 decree banned the use of GM corn in food for human consumption (dough and tortillas). Second, the 2023 decree instructed Mexican government agencies to gradually phase out the use of GM corn in all products for human and animal consumption.

The United States raised seven legal claims under the USMCA, specifically the provisions regarding National Treatment and Market Access for Goods (Chapter 2) and Sanitary and Phytosanitary Measures (Chapter 9). The United States asserted that the two measures in the 2023 decree were not based on science and undermined the USMCA’s provisions for market access. Mexico disputed all of the US claims and argued that the measures under the 2023 decree were consistent with the USMCA, the protection of human health, and the rights of Indigenous people.

The three-person USMCA panel agreed with the United States on all claims. In a lengthy decision, the panel ruled that Mexico’s measures were inconsistent with several USMCA provisions of Chapters 2 and 9. The panel reasoned, among other conclusions, that (1) Mexico’s measures were not based on relevant scientific principles or international standards, (2) Mexico did not conduct a risk assessment to consider such standards, and (3) Mexico improperly restricted the importation of goods of another USMCA signatory. The panel concluded that Mexico’s measures were unjustified and did not fall under any exception of the USMCA (e.g., the Indigenous peoples’ rights exception established in Article 32.5 of the USMCA). Thus, the panel recommended that Mexico align its measures to conform to its obligations under the USMCA.

Under the USMCA Chapter 31 rules, Mexico has 45 days from December 20, 2024, the date of the final report, to comply with the panel’s findings. Mexico has indicated that it will cooperate with the panel’s determination. Mexico’s press release can be found here.

The dispute’s outcome represented a victory for American corn exporters, for whom the Mexican market is critical. As indicated by the Office of the US Trade Representative (USTR), Mexico is the United States’ largest export market for corn, with the United States exporting $4.8 billion of corn to Mexico during the first 10 months of 2024.

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