WASHINGTON (AP) — President Donald Trump said Saturday that he has instructed Homeland Security Secretary Kristi Noem not to intervene in protests occurring in cities led by Democrats unless local authorities ask for federal help amid mounting criticism of his administration’s immigration crackdown.

On his social media site, Trump posted that “under no circumstances are we going to participate in various poorly run Democrat Cities with regard to their Protests and/or Riots unless, and until, they ask us for help.”

He provided no further details on how his order would affect operations by U.S. Customs and Immigration Enforcement and DHS personnel, or other federal agencies, but added: “We will, however, guard, and very powerfully so, any and all Federal Buildings that are being attacked by these highly paid Lunatics, Agitators, and Insurrectionists.”

Trump said that in addition to his instructions to Noem he had directed “ICE and/or Border Patrol to be very forceful in this protection of Federal Government Property.”

The Trump administration has already deployed the National Guard, or federal law enforcement officials, in a number of Democratic areas, including Washington, Los Angeles, Chicago and Portland, Oregon. But Saturday’s order comes as opposition to such tactics has grown, particularly in Minnesota’s Twin Cities region.

Minnesota Attorney General Keith Ellison and the mayors of Minneapolis and St. Paul have challenged a federal immigration enforcement surge in those cities, arguing that DHS is violating constitutional protections.

A federal judge says she won’t halt enforcement operations as the lawsuit proceeds. State and local officials had sought a quick order to halt the enforcement action or limit its scope. Justice Department lawyers have called the lawsuit “legally frivolous.”

The state, particularly Minneapolis, has been on edge after federal officers fatally shot two people in the city: Renee Good on Jan. 7 and Alex Pretti on Jan. 24. Thousands of people have taken to the streets to protest the federal action in Minnesota and across the country.

Trump’s border czar, Tom Homan, has suggested the administration could reduce the number of immigration enforcement officers in Minnesota — but only if state and local officials cooperate. Trump sent Homan to Minneapolis following the killings of Good and Pretti, seeming to signal a willingness to ease tensions in Minnesota.

Will Weissert, The Associated Press