The Trump administration is cracking down on "sanctuary" cities and counties that do not cooperate with the federal government in enforcing U.S. immigration law.

Attorney General Jeff Sessions took the podium at the White House press briefing on Monday and threatened to pull funding from cities that refuse to notify Immigration and Customs Enforcement (ICE) when they have illegal immigrants in custody.

Sessions' threat drew a defiant response from several sanctuary city mayors, with New York City Mayor Bill de Blasio calling it "saber-rattling" and Chicago Mayor Rahm Emanuel declaring that a denial of federal funds is "unconstitutional."

On "Outnumbered" today, Bill O'Reilly said de Blasio, Emanuel and all the mayors of sanctuary cities are simply pandering to their constituents, and it's going to come back to bite them.

"What they - the sanctuary city people - are saying is, 'We want anarchy,'" O'Reilly said.

He explained that not only are sanctuary cities not notifying ICE when they have an illegal immigrant in custody, they're refusing to detain them and releasing potentially dangerous criminals back into the public.

"The Justice Department has $4.5 billion this year to award - in a bidding process - cities and counties who are doing good, innovative police programs," O'Reilly said. "It's their opinion who gets the money. It's not mandated money."

"San Francisco, Chicago, New York City, they're not going to get that, because they're not cooperating. ... It hurts the residents of those towns."

Watch more above, and see Jan Brewer call out "unbelievable" sanctuary policies.

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