Border czar Tom Homan said Tuesday that Immigration and Customs Enforcement teams are already arresting "public safety threats."

"No, it started. ICE teams are out there as of today," Homan told Fox News on Tuesday. "We gave them direction to prioritize public safety threats that we're looking for. We've been working up the target list."

The Trump administration had promised to start a "historic" mass deportation operation.

"There was some discussion about Chicago because the specific operational plan was released," Homan said. "So we had to look at and reevaluate, ‘Does this raise officer safety concerns?’ And it does. But we've addressed that and teams are out there, effective today."

The operation is prioritizing public safety threats, but Homan said that no one is "off the table" when it comes to arresting illegal immigrants.

"Right out of the gate, it’s public safety threats, those who are in the country illegally that have been convicted, arrested for serious crime," he explained. "But let me be clear: there's not only public safety threats that will be arrested, because in sanctuary cities, we're not allowed to get that public safety threat in the jail, which means we got to go to the neighborhood and find him."

"And when we find him, he may be with others. And unlike the last administration, we're not going to tell our ICE officers not to arrest an illegal alien. So if they find others, they will be arrested. So sanctuary cities will get exactly what they don't want -- more agents in their neighborhoods and more collateral arrests," Homan said.