Immigration officers began arresting illegal migrants who pose threats to “public safety” of which there are 700,000 roaming the country, Homan said Wednesday.

Border czar Tom Homan said Tuesday that ICE agents are already being deployed across the U.S. to engage in a mass deportation operation.

Immigration and Customs Enforcement has had a tip line for more than 20 years. Some advocates support the proposal anyway, but others are skeptical.