White House border czar Tom Homan is promising to “flood” cities run by Democrats with immigration agents, as the Trump administration ramps up border enforcement.

Congress earlier this month gave the Trump administration more than $170 billion over the next four years to dramatically scale up enforcement, detention and deportation, and Homan said Americans living in so-called “sanctuary cities” can expect to see far more agents on the street soon.

The White House has repeatedly singled out cities from Los Angeles to Denver to Boston for their refusal to assist ICE agents making detentions, and Homan has threatened to arrest elected officials who stymie the president.

Migrant-rights groups warn increased enforcement raises the risk of more civil rights violations and violent confrontations, like the chaotic protests that broke out in Los Angeles last month following Immigration and Customs Enforcement raids at a Home Depot, among other locations.

Trump officials have long complained that many cities run by Democrats refuse to honor requests to detain people on behalf of ICE in local jails, and Homan said doing so makes it harder for ICE to arrest “bad guys” in the safety of a detention center. He said making street arrests is more dangerous for everyone, requiring more personnel to operate safely.

The increased funding for one of Trump’s signature policies comes as the American public appears to be growing increasingly concerned about the tactics being deployed. A July 20 poll by CBS/YouGov found that 56% of Americans disapproved of the president’s immigration measures, while 44% approved, a 10-point drop from February.