USMCA panel rules Mexico ban on imported GMO corn violates trade rules

A day after losing a USMCA decision on GMO corn imports, President Claudia Sheinbaum said Mexico would enact a law against the planting of transgenic corn in order to protect the country’s biodiversity and cultural heritage. A three-member USMCA panel ruled unanimously in favor of the United States that Mexico’s 2023 ban on imported GMO corn was an unjustified trade barrier.

U.S. farm groups said the ruling was a major victory, “an incredible development for the nation’s corn growers and rural communities,” said the National Corn Growers Association. The American Farm Bureau Federation said the decision affirmed “biotech corn is safe and decisions must be based on science, not politics.”

Mexico is the No. 1 customer for U.S. food and ag exports, and purchased $4.8 billion of U.S. corn during fiscal 2024, the most of any country. Almost all U.S. corn is grown from GMO seeds. Corn is the second-largest U.S. ag export, behind soybeans.

Under USMCA rules, Mexico has 45 days to comply with the ruling. The 2023 presidential decree imposed an immediate ban on imports of GMO white corn used in making dough and tortillas, an everyday food of Mexico, and gradual elimination of imported GMO corn for industrial food uses and for livestock feed. So-called yellow corn is fed to livestock.

“The Mexican Congress, here with the help of the senators and deputies, we are going to reverse this resolution,” said Sheinbaum on Saturday, referring to the USMCA decision. “They are going to legislate, I am sure, that transgenic corn cannot be planted and that Mexico’s biodiversity must be protected in our country. As we say, ‘Without corn, there is no country,'”

Corn originated in Mexico and holds deep cultural significance in the country; it has five dozen native varieties. Conservationists, Indigenous communities, and traditional farmers have sought for two decades to keep the country’s heritage seeds free of GMO traces.

By contrast, U.S. farmers quickly embraced GMO corn varieties when they came on the market in the mid-1990s. The United States, an agricultural powerhouse, is a world leader in agricultural biotechnology and fiercely defends the safety of biotech food. The USMCA, like its predecessor NAFTA, calls for tariff-free trade in food and agriculture for the most part.

“The panel’s ruling reaffirms the United States’ longstanding concerns about Mexico’s biotechnology policies and their detrimental impact on U.S. agricultural exports,” said U.S. trade representative Katherine Tai. “It underscores the importance of science-based trade policies that allow American farmers and agricultural producers to compete fairly and leverage their innovation to address climate change and enhance productivity.”

Mexico’s prohibitions were not based on relevant international standards, relevant scientific principles, or risk assessments, said the dispute panel in its decision. “Accordingly, the panel recommends that Mexico bring its measures into conformity with USMCA obligations … The panel accepts that Mexico is seeking to address genuine concerns in good faith, and suggests that such concerns be channeled into an appropriate risk assessment process, measures based on scientific principles, and in dialogue among all USMCA parties to facilitate a constructive path forward.”

The 2023 decree that banned GMO corn imports also instructed Mexican officials to abstain from use of GMO corn and the weedkiller glyphosate “within the framework of public programs or other government activity” and to find “sustainable and culturally appropriate alternatives” to glyphosate. Those provisions were not part of the U.S. challenge, which focused on trade barriers to GMO corn.

President-elect Trump has threatened to impose 25-percent tariffs on Mexican and Canadian products as soon as he takes office on Jan. 20 unless they take sufficient action against drug smuggling and illegal immigration. The USMCA, a keynote of Trump’s first term in office, was due for review in 2026.

The USMCA panel ruling was available here.