Why is Mexico standing up to bigger neighbours US, Canada on corn?

Mexico has barred the import of GMO corn for human consumption, raising the ire of exporter US where most corn is GMO. https://www.aljazeera.com/economy/2023/9/22/why-is-mexico-standing-up-to-bigger-neighbours-us-canada-on-corn?traffic_source=rss&feed_id=8784&_unique_id=650e2433c2b4e