The first military flights to deport migrants from the United States to Naval Base Guantanamo Bay were slated to take off Tuesday.

A U.S. official says the first U.S. military flight to deport migrants from the United States to Guantanamo Bay has departed and is expected to arrive later this evening

There are approximately 300 service members supporting the holding operations at Guantanamo Bay, and the numbers will fluctuate based on the requirements of the Department of Home

The Trump administration on Tuesday began flights transporting "criminal aliens" to Guantanamo Bay, with plans in the works to use the Cuban detention facility to eventually hold thousands of other migrants.

As tents went up in Guantanamo Bay, Cuba to hold migrants, attorneys at the Department of Homeland Security and Pentagon were still trying to determine whether it was legal to take the unprecedented step of flying migrants from the US southern border to the facility,

The first flight carrying migrants to Guantanamo Bay arrived Tuesday evening, a U.S. Transportation Command official said.