The Trump administration filed lawsuits Thursday against four Democrat-led states after they refused to provide confidential license plates to Immigration and Customs Enforcement agents, escalating a growing battle over cooperation with the federal government’s immigration enforcement efforts.

The Department of Justice announced legal action against Maine, Massachusetts, Oregon, and Washington, accusing the states of unlawfully blocking ICE agents from obtaining undercover vehicle registrations commonly used by law enforcement agencies during sensitive operations.

According to the lawsuits, the states declined to reverse policies denying ICE access to the confidential plates, which the administration says are necessary for agents carrying out arrests as part of President Donald Trump’s immigration crackdown.

Officials in Maine and Massachusetts had previously defended their stance by pointing to what they described as aggressive ICE enforcement tactics, arguing that state resources should not be used to assist covert civil immigration operations.

The lawsuits follow warnings issued earlier this month by Assistant U.S. Attorney General Brett Shumate, who sent letters to state officials threatening legal action if the policies remained unchanged.

The Justice Department argues that the states are violating the Constitution by discriminating against federal agencies, specifically ICE and other branches of the Department of Homeland Security, while continuing to cooperate with other law enforcement entities engaged in undercover investigations.

Federal officials also contend that denying the confidential plates places immigration agents at risk by making them more vulnerable to identification, tracking, harassment, and possible attacks while performing arrests.

“Law enforcement officers risk their lives every day to keep Americans safe and must be able to carry out their ⁠duties effectively,” Acting U.S. Attorney General Todd Blanche said in a statement.

Representatives for the governors of Maine, Oregon, and Washington did not immediately respond to requests for comment following the announcement of the lawsuits.

A spokesperson for Massachusetts Governor Maura Healey instead referred reporters to a letter her administration sent to the Justice Department last week defending the state’s policy.

In that letter, Healey’s administration argued that the Massachusetts Registry of Motor Vehicles applies the policy broadly and does not single out federal immigration authorities. The state maintained that confidential license plates are restricted not only for federal agencies, but also for state and local law enforcement unless the request involves criminal investigations.

The Justice Department disputed that claim in its lawsuit, asserting that until recently — including as late as 2025 — federal agencies such as ICE and Customs and Border Protection routinely received confidential vehicle registrations and plates in Massachusetts.

According to the complaint, the policy shifted earlier this year after Healey’s administration announced it would no longer assist ICE operations in that manner.