The deployment, announced on Friday by Texas officials, comes after Trump directed Defense Secretary James Mattis to request the use of National Guard personnel to help the Department of Homeland Security secure the border in four southwestern US states, including Texas.
Mattis on Friday authorised the funding for up to 4,000 National Guard troops for the operation through September 30, a Department of Defense memo showed.
The troops will be under the “command and control” of their respective governors, it said.'
Trump has failed so far to persuade either the Mexican government or the US Congress to fully fund a wall he wants to build along the border. Mexican President Enrique Pena Nieto on Thursday sharply rebuked Trump over the plan.
The Texas Army National Guard said 250 guardsmen along with aircraft, vehicles and surveillance equipment were to be deployed along the state’s border with Mexico within the next 72 hours.