U.S. authorities last week seized 43,000 rounds of ammunition in two separate stops at one of the four international border crossings in Nogales, Arizona.

In a Monday social media post, U.S. Ambassador to Mexico Ronald Johnson said the seizure at the Mariposa Port of Entry reaffirms the U.S. government’s commitment to disarming drug cartels and stopping the illegal flow of weapons to Mexico.

Johnson said the operations involved U.S. Customs and Border Protection (CBP) and its Office of Field Operations (OFO), as well as federal agents from Tucson, Arizona. 

The identities of the suspected smugglers have not been released.

The CBP action was originally disclosed on June 18. OFO Executive Assistant Commissioner Diane J. Sabatino said in a social media post that CBP officers discovered 40 boxes containing 15,000 rounds of ammunition in one vehicle and 44 boxes containing 28,000 rounds of 7.62×39 ammunition in another. The 7.62×39 ammunition is used in assault weapons such as the AK-47.

Johnson said the U.S. operation “demonstrates the value of advanced non-intrusive inspection technology for identifying and stopping illicit activities.”

These technologies allow for the inspection of vehicles and goods without the need for an initial physical inspection, facilitating the detection of weapons, ammunition and other illegal products.

“No matter what method is used, criminals should know that we will find them,” Johnson said, adding that cooperation between Mexico and the United States contributes to strengthening the security of both nations.

STOPPED AT THE PORT
Same port. Same day. Two outbound seizures.
CBP officers discovered 40 boxes containing 15,000 rounds of ammunition in one vehicle and 44 boxes containing 28,000 rounds of 7.62×39 ammunition in another.
A total of 43,000 rounds stopped at the port.#OFOproud🇺🇸 pic.twitter.com/huIxmniuc2

— Executive Asst. Commissioner Diane J. Sabatino (@OFOEAC) June 18, 2026

The Mariposa port of entry is one of the main trade crossings between Mexico and the United States, primarily comprising freight transport operations. It is among the strategic checkpoints used by U.S. security agencies to identify activities related to cross-border trafficking.

This month’s bust comes three months after CBP reported that members of the Nogales Contraband Enforcement Team seized more than 47,000 rounds of ammunition headed to Mexico during four weeks in February. 

Just a few weeks later, CBP officers at the same port of entry seized more than 120 pounds of methamphetamine in two separate enforcement actions. 

With reports from La Jornada, Uno TV and La Silla Rota