The Pentagon has approved the exchange of $1bn (£758m) to armed force engineers for new divider development along the US-Mexico fringe.
The assets are the first under the national crisis announced by President Donald Trump to sidestep Congress and assemble the boundary he vowed amid his race crusade.
Democrats have challenged the move.
The assets will be utilized to work around 57 miles (91km) of fencing.
President Trump has considered the circumstance at the southern fringe an “emergency” and demands a physical obstruction is expected to stop crooks crossing into the US. His commentators state he has produced the outskirt crisis.
A Pentagon explanation said acting US Defense Secretary Patrick Shanahan had “approved the officer of the US Army Corps of Engineers to start arranging and executing up to $1bn in help to the Department of Homeland Security and Customs and Border Patrol”.
Trump faces resentment regarding divider crisis plan
A noteworthy land get by Trump
The announcement refered to a government law that “gives the Department of Defense the specialist to build streets and wall and to introduce lighting to square medication carrying hallways crosswise over global limits of the United States in help of counter-opiate exercises of administrative law authorization offices”.
Also the 18ft-high (5m) “person on foot fencing”, the assets will cover street enhancements and new lights.
Just legislators grumbled that the Pentagon had not looked for consent from the suitable advisory groups before telling Congress of the assets exchange.