Attorney General William Barr announced new measures to combat sanctuary cities in what he called a “significant escalation.”

Barr, 69, made the announcement on Monday at the National Sheriff’s Association 2020 Winter Legislative and Technology Conference. He said that the Justice Department would file a number of lawsuits against state and local governments and new reviews of sanctuary cities and prosecutors.

One of the lawsuits targets a New Jersey law enforcement directive that Barr said stops officials from sharing the immigration status of those in custody and requires authorities to notify those detained if Immigration and Customs Enforcement files an immigration detainer request.

“The department is filing a complaint against the state of New Jersey seeking declaratory and injunctive relief against its laws that forbid state and local law enforcement from sharing vital information about criminal aliens with [the Department of Homeland Security],” Barr said.

Another of the lawsuits goes after King County, Washington, over a policy “that forbids DHS from deporting aliens from the United States using King County International Airport,” the attorney general said.

“Further, we are reviewing the practices, policies, and laws of other jurisdictions across the country. This includes assessing whether jurisdictions are complying with our criminal laws, in particular the criminal statute that prohibits the harboring or shielding of aliens in the United States,” Barr announced at the event.

He also said that the Justice Department is conducting reviews of district attorneys who have enacted policies that charge “foreign nationals with lesser offenses for the express purpose of avoiding the federal immigration consequences of those nationals’ criminal conduct.”

Barr invoked the supremacy clause of the Constitution, saying, “The Founding Fathers carefully divided responsibility and power between the federal government and the state governments.”