MEXICO CITY (Reuters) -Mexico's meat industry is pushing back against new government regulations on livestock movement as tensions with the United States heat up over an outbreak of the flesh-eating screwworm parasite.

Restricting movement of livestock from the south to the north of the country "threatens the viability of a sector that generated $192 billion in 2024," Mexican meat chamber AMEG said in a statement released on Friday. 

"Recent measures... jeopardize the supply chain of the meat production sector," AMEG said without specifying which measures. It said the only proven method to eradicate the screwworm, which infests and can kill livestock if untreated, was the release of sterile flies to reduce the mating population in the wild. 

A document dated September 19 from Mexico's agriculture ministry and sanitation agency Senasica, seen by Reuters and confirmed by a Senasica spokesperson, said the anti-parasite drug ivermectin must be given 72 hours in advance of the movement of cattle under the supervision of staff from the International Regional Organization for Animal and Plant Health. 

U.S. Agriculture Secretary Brooke Rollins blamed a confirmed case of screwworm last week in Mexico's Nuevo Leon state, less than 70 miles (113 km) from the U.S. border, on Mexico's failure to curb cattle movements and tend to fly traps that monitor the wild population.    

The Mexican document detailing the new requirement for ivermectin use was sent to sector professionals by the government via email, according to a Mexican industry official who asked not to be identified. The ivermectin requirement would substantially delay livestock movement, the official said. 

Mexico has battled to contain the outbreak that has moved northwards from Central America. The pest, which officials have said has not yet crossed the U.S. border, poses a multibillion-dollar risk to the country's beef industry. The U.S. government has kept its border mostly closed to Mexican cattle imports since May.

U.S. cattle producers, including industry group R-CALF USA, have publicly called on the U.S. government to persuade Mexico to halt the northward movement of livestock and the illegal trafficking of cattle originating from other Latin American countries. 

Mexican President Claudia Sheinbaum said last week the country was working on new measures that would soon be announced, but said restricting livestock movement from the south to the north was not simple.    

Senasica told Reuters on September 25 that its fly trap system is checked every three or four days, a frequency that was jointly determined with U.S. counterparts, and that it has implemented a double inspection system at the livestock's point of origin.