(CNN) The acting head of Immigration and Customs Enforcement, Mark Morgan, provided some details Wednesday on plans to execute an operation targeting families who have gone through their legal proceedings.

"If you're here illegally, then you should be removed," Morgan told reporters during a call. "And in this case, that includes families."

President Donald Trump tweeted Monday night that ICE was preparing to deport "millions" of undocumented immigrants next week, but he fell short of offering details. The vague announcement was striking, given the figure and the decision to disclose an operation prior to its execution.

Morgan on Wednesday refrained from providing a time frame or details on the scope of the operation. The intent, Morgan said, is to deter migrants from coming to the US-Mexico border, and the operation is expected to include families who are on an expedited court docket. It remains unclear if the President was referring to this operation in his tweet.

Last year, the Executive Office for Immigration Review, which oversees the nation's immigration courts, announced that it had begun tracking family cases filed by the Department of Homeland Security in 10 immigration court locations: Atlanta, Baltimore, Chicago, Denver, Houston, Los Angeles, Miami, New Orleans, New York and San Francisco.

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