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After Continued Pressure from Ernst, USTR Finally Takes Action on Mexico’s Ban on U.S. Corn

Last year, Senators Ernst and Grassley led a letter to the USTR demanding intervention in Mexico’s plan to end U.S. genetically modified corn imports.

WASHINGTON – U.S. Senator Joni Ernst (R-Iowa), a member of the Senate Agriculture Committee, successfully forced the United States Trade Representative (USTR) to engage with Mexico to dispute the country’s ban on genetically modified corn.


“After continued pressure from me and my colleagues, I’m glad to see USTR is finally working to address Mexico’s absurd and baseless biotech corn ban. As the top corn-producers in the country, Iowa farmers have been anxiously awaiting this announcement. The U.S. must hold Mexico accountable to their science-based commitment under USMCA and defend the livelihoods of hard-working Iowans,” said Ernst.


The action comes following continued pressure by Senators Ernst and Chuck Grassley (R-Iowa) on behalf of Iowa farmers. Mexico’s decision, a clear violation of the U.S.-Mexico-Canada Agreement (USMCA), would stifle the market for Iowa corn growers who export 16 million tons of corn to Mexico each year.



  • Senators Ernst and Grassley are members of the Senate Agriculture Committee and were champions of the USMCA.
  • On November 14, 2022, the Iowa senators sent a joint letter to USTR sounding the alarm on Mexico’s plan to ban U.S. genetically modified corn imports.
  • On December 14, 2022, a bipartisan group of senators sent a letter to USTR Ambassador Katherine Tai and USDA Secretary Tom Vilsack expressing their concerns over Mexico’s decree.
  • Mexico’s proposed ban would effectively phase out the import of 90 percent of U.S. corn by January 2024.