U.S. Threatens Livestock Import Ban Over Mexico's Screwworm Control

The Trump administration warned Saturday it would restrict livestock imports from Mexico unless efforts against the New World screwworm pest are intensified. U.S. Agriculture Secretary Brooke Rollins sent a letter to her Mexican counterpart, stating imports of animal commodities will be limited if Mexico does not act by Wednesday.

Rollins posted the letter on social media platform X, highlighting that Mexico had restricted aerial spraying operations to six days a week and imposed heavy customs duties on aircraft parts essential for pest control. The warning adds to existing trade tensions as President Donald Trump escalates tariffs on Mexico and other key partners.

New World screwworms, whose maggots infest the skin of living animals, can cause severe injuries and even death. The pest threatens livestock, wildlife, and in rare cases, humans. Mexico was previously the largest cattle supplier to the U.S., but imports have sharply dropped. Last month, the U.S. imported only 24,000 head of cattle from Mexico, compared to 114,000 a year earlier, according to the U.S. Department of Agriculture.

The U.S. had temporarily blocked Mexican livestock shipments in late November after detecting the pest but lifted the ban in February following new health protocols for imported animals. Rollins' latest threat reflects growing frustration over Mexico’s handling of the outbreak.

A drone image captured livestock at a Chihuahua Regional Livestock Union facility near Ciudad Juarez, preparing for export after the U.S. resumed cattle imports under stricter health rules.

Rollins' letter, first reported by Fox News, underscores the urgency for Mexico to strengthen its screwworm eradication measures to avoid another disruption in cattle trade.