It was not immediately clear what units and service branches would be tapped for the deployment, but the announcement comes amid the Trump administration's executive actions directing a comprehensive military border mission.

The Pentagon said Wednesday it has begun deploying 1,500 active-duty troops to the southern border, putting in motion plans President Trump laid out in executive orders shortly after he took office to crack down on immigration.

The Pentagon’s Transportation Command will use military aircraft to send more than 5,000 undocumented immigrants from San Diego and El Paso, Texas, who are detained by Customs and Border Protection, Acting Defense Secretary Robert Salesses said in a statement. The troops also will assist in building new border fences and barriers.