Mexican Agriculture Minister Julio Berdegue, speaking at a regular press conference alongside President Claudia Sheinbaum, ruled out closing Mexico's southern border to cattle from Central America, but acknowledged it will take a long time to eradicate the pest.

The screwworm is a larva of the Cochliomyia hominivorax fly that can invade the tissues of any warm-blooded animal, including humans.

The New World screwworm is endemic in parts of Latin America and the Caribbean — and its northward spread into Mexico has alarmed U.S. officials. It can kill a full-grown cow in one to two weeks.