SANTA FE, N.M. (AP) — The Trump administration is adding another militarized zone to support border security operations — this time in California. The Department of Interior on Wednesday stated that jurisdiction along most of California’s international border with Mexico will be transferred to the Navy to enhance public land security. The newly designated militarized zone spans nearly from the Arizona state line to the Otay Mountain Wilderness, including the Imperial Valley and border communities like Tecate.

Since April, extensive sections of the border have been designated as militarized zones, granting U.S. troops the authority to detain immigrants and others accused of trespassing on military bases, along with enabling additional criminal charges that could lead to prison sentences. Over 7,000 troops have already been deployed, along with various helicopters, drones, and surveillance tools.

This military strategy started in April on a 170-mile (275-kilometer) stretch in New Mexico and has since been expanded to parts of Texas and Arizona. The Interior Department described the new national defense area in California as a hotspot for unlawful crossings, although Border Patrol arrests have plummeted to the slowest rate since the 1960s amid President Trump’s push for immigration enforcement.

The initiative was met with concern as legal experts have highlighted a potential violation of laws prohibiting military involvement in law enforcement on U.S. soil. The new zone was announced alongside a federal ruling that ordered the cessation of California National Guard troop deployments in Los Angeles, returning control of these forces to the state, a move that prompted Trump to call up over 4,000 troops in June without state approval to further immigration enforcement efforts.