Mexico banned GMO corn. The USA demands Mexico on the base of the free trade act and wins having Science determine that GMO food is not bad for you and is needed to fight climate change. They pretty much used fake science to overturn Mexico sovereign decision to not consume GMO corn.

Why are GMOs banned in countries?
Because over 80% of GMO crops grown around the world have been engineered for herbicide tolerance, resulting in a significant increase in the use of toxic herbicides, increasing its negative impact on the environment and human health. Several countries around the world have banned the use of GMOs.

Source :

https://ustr.gov/about-us/policy-offices/press-office/press-releases/2024/december/united-states-prevails-usmca-dispute-biotech-corn