The Department of Agriculture on Friday announced a phased reopening of the southern border to livestock imports from Mexico after determining the country had increased its efforts to combat the flesh-eating New World screwworm.

The USDA said in a news release the first port will reopen in Douglas, Arizona, on Aug. 24, followed by Columbus, New Mexico, on Sept. 14 and Santa Teresa, New Mexico, on Sept. 21, provided conditions continue to improve.

The Biden administration initially cut off cattle imports in November 2024 after a screwworm case was detected in southern Mexico. The policy was reversed shortly after President Donald Trump's 2025 inauguration, but it was implemented again a few months later as the pest moved northward in Mexico.

Mexico typically sends about a million calves across the border each year, accounting for roughly 5% of the cattle processed in the U.S., The Wall Street Journal reported Friday.

The loss of those cattle has exacerbated a shortage of livestock that has squeezed meatpackers and sent prices for ground beef and steaks to record highs.

Retail ground-beef prices averaged $6.83 a pound through June, according to Bureau of Labor Statistics data. That is an 11.5% increase over the same point last year.

The average price of USDA choice sirloin steak is $14.45 a pound, an 11.8% increase over the same period last year.

Agriculture Secretary Brooke Rollins said in the release that the border decision was made primarily with the protection of U.S. herds in mind.

"Protecting the United States from NWS [New World screwworm] and pushing this pest out of Mexico and back to the Darien Gap is a top priority at USDA and has the full attention of the Trump administration," Rollins said. "The closure of the Southern ports of entry for the last year has been a tough but necessary action to control the spread of NWS in Mexico and protect the American livestock industry.

"Thanks to the work across the federal government as well as state, local, and industry partners, it is now safe to reopen the Douglas, Arizona, port in 30 days to resume the hundreds-year-old movement of cattle."

The move is contentious, with U.S. ranchers concerned about the spread of a parasite with a history of thinning herds and raising costs, according to the Journal.

Meanwhile, meat-industry executives said opening the border is safe and one of the quickest ways to ease beef prices and relieve financial pressure on cattle production in the Southwest.

The parasitic fly had been absent from the U.S. since the 1960s. But in June, agriculture officials identified it in a 3-week-old Texas calf.

Dozens of U.S. cases have been confirmed since then, with the fly appearing on cattle and other animals. All the cases have been reported in Texas except one involving a dog in New Mexico.

Rollins told the Journal that closing the border gave the USDA time to increase construction of sterile-fly facilities, improve surveillance for the parasite along the border, and improve screening procedures for imported cattle.

For example, Mexican cattle will move through a disinfectant dip vat when entering a U.S. port of entry. Female screwworm flies mate only once, so sterile male flies help suppress the parasite's population. Rollins said the situation is now under control.

The USDA said only cattle and bison born and raised in Sonora or Chihuahua, or treated under the agency's screwworm protocols before entering those states, will initially be eligible for import.

Other Texas ports will reopen only if neighboring Mexican states adopt the same screwworm-control safeguards.

Some ranchers, including the cattle-trade group R-Calf, which has gained favor among top Trump administration officials, have argued against reopening the border.

Bill Bullard, chief executive of R-Calf, told the Journal the border should stay shut until the parasite is completely eradicated to protect American cattle.

"This is a real threat to U.S. livestock," he has said.