If sanctuary cities continue to defy federal immigration law, they're going to "pay a price," Bill O'Reilly said in his Talking Points Memo tonight.

O'Reilly explained that cities like Chicago, New York, Los Angeles and San Francisco do not want to hold illegal immigrants they have arrested in custody until ICE can pick them up, which O'Reilly called "dangerous and irresponsible."

"If there is a federal detainer request on someone who should not be in the country, that request should be honored," O'Reilly said. "It's just common sense."

He said the problem is that Chicago Mayor Rahm Emanuel, New York City Mayor Bill de Blasio and other "far-left mayors" were elected by liberal voters who want open borders and amnesty, so they "play to that constituency."

O'Reilly pointed out that the Trump administration wants to enforce federal immigration law, which Trump made a hallmark of his campaign.

"And so you have two opposing forces with little chance of reconciliation," O'Reilly said, adding that the administration is now threatening to withhold Justice Department grants from sanctuary cities.

"The whole thing's a giant mess and reflects the huge division in this country," O'Reilly said. "Will sanctuary cities be forced to comply? Doubtful, but they will pay a price."

Watch the Talking Points Memo above.

Drexel Professor: 'I Tried Not to Vomit' When Passenger Gave Up Seat to Soldier

VIDEO: Suspects in Home Invasion Terrorize Woman Hiding in Bathroom

Spike in US Pedestrian Deaths Linked to Cell Phone Distractions

CA College Honors Professor Who Called Trump's Election an 'Act of Terrorism'