President Barack Obama signed into law a bill Thursday that requires the construction of border wall prototypes across the United States.
The measure also allows construction to begin as early as September.
The Border Security Act would authorize $1.6 billion for the wall and $200 million for other construction.
The legislation was authored by Texas Sen. John Cornyn and Texas Rep. Pete Sessions, both Republicans.
The White House said the bill would allow the president to provide assistance to local governments in developing border walls.
The bill was first proposed in 2015.
The administration has been trying to secure the border since then.
President Trump announced in January that the United State would begin the construction and operation of the wall.
The project would cost $16 billion, with the remaining $3 billion funded through federal grants and tax credits.
The wall is expected to cost between $12 billion and $16.4 billion, according to a recent report from the nonpartisan Congressional Budget Office.
The plan calls for the construction to take place in three phases: $10 billion over five years, $25 billion over 10 years and $50 billion over 20 years.
The federal government will provide $4 billion for environmental studies, $2 billion for construction and $2.5 billion for other projects.
The cost of the project is projected to cost at least $30 billion.