The Pentagon has authorized the Department of Homeland Security (DHS) to temporarily test a military-grade heat ray that could eventually be used in operations along the U.S.-Mexico border, under a memo signed by Secretary of War Pete Hegseth last month.

The weapon, officially known as the Active Denial System (ADS), uses an invisible beam of electromagnetic energy to create an intense burning sensation on a person's skin without relying on conventional ammunition. According to the U.S. military, the system can project its energy beam slightly more than half a mile.

Military officials have compared the sensation to the intense heat experienced when opening a hot oven. The resulting effect typically lasts between 10 and 15 minutes and produces what officials describe as an instinctive urge to move away from the beam.

The authorization marks a potential new development in the Trump administration's efforts to strengthen border security and expand the tools available to immigration enforcement agencies. Although the system has never been deployed along the southern border, Customs and Border Protection officials have discussed its possible use for crowd dispersal in areas experiencing high concentrations of illegal crossings.

The DHS request did not specify where or how the weapon would be tested, nor did it establish a final plan for its operational use. Previous discussions among current and former border officials have included the possibility of deploying the technology to disperse crowds near the U.S.-Mexico border.

The memo authorizes the temporary loan of one Active Denial System for seven months beginning in September. It also specifies that the system will not be operated by Department of War personnel, leaving DHS responsible for determining how it is tested and potentially employed.

Under the agreement, DHS will oversee the system's use and develop the tactics, techniques and procedures governing its operation. After the seven-month period expires, the department may submit another request to extend access to the system for border operations.

Customs and Border Protection said it continues to evaluate new technologies that could improve its operational capabilities.

“CBP is continually evaluating new technologies, especially those that enhance operational effectiveness and strengthen mission capabilities,” a spokesperson said.

The Active Denial System has previously undergone military testing and limited deployment. The U.S. military briefly deployed the technology to Afghanistan nearly two decades ago but ultimately chose not to use it in active combat operations.

Military officials also considered employing the system for crowd control at U.S. facilities overseas where terrorist detainees were held, but ultimately declined to use it for that purpose.

The possibility of using the heat ray domestically has also surfaced in previous deliberations. Authorities considered deploying the technology during periods of domestic unrest near the end of President Donald Trump's first term, when protests erupted following the 2020 murder of George Floyd.

Despite those discussions, the system has never been deployed for crowd control along the U.S.-Mexico border.

The latest authorization allows DHS to evaluate the technology and develop potential operational procedures, but it does not confirm that the heat ray will ultimately be used against migrants or other individuals at the border. Any future deployment will depend on testing, operational assessments and subsequent decisions by federal officials.