Acting Defense Secretary Patrick Shanahan notified Congress Monday that the Pentagon has authorized $1 billion to build 57 miles of "pedestrian fencing" along the US-Mexico border.
According to the statement, the fencing will be 18 feet high and will be erected within the Yuma and El Paso Sectors of the border. The funds will also go towards "constructing and improving roads, and installing lighting."
President Donald Trump sought the funds after declaring a national emergency on the southern border last month.
Bloomberg reports that a group of Democratic senators condemned the move as a violation of congressional appropriations. The lawmakers wrote a letter to Shanahan Monday voicing their "serious concerns."
"The $1 billion reprogramming that the department is implementing without congressional approval constitutes a dollar-for-dollar theft from other readiness needs of our Armed Forces," the senators wrote.
However, the Pentagon's statement says section 284 "gives the Department of Defense the authority to construct roads and fences and to install lighting to block drug-smuggling corridors across international boundaries of the United States in support of counter-narcotic activities of Federal law enforcement agencies."
The Pentagon's announcement comes before House Democrats try to override Trump's first veto in a vote set for Tuesday. Trump vetoed a resolution last month that sought to block his declaration of a national emergency.
Tuesday's vote to override his veto is expected to fail, which could allow Trump's national emergency declaration and $1 billion in new funds to move forward.