Six companies hired by the Trump administration began to construct prototypes of a U.S.-Mexico border wall on Tuesday.
"We are committed to securing our border and that includes constructing border walls," U.S. Customs and Border Protection acting deputy commissioner, Ronald Vitiello, said in a statement Tuesday, according to NPR.
"Our multi-pronged strategy to ensure the safety and security of the American people includes barriers, infrastructure, technology and people. Moving forward with the prototype enables us to continue to incorporate all the tools necessary to secure our border," Vitiello added.
The companies began to construct the prototypes near the border in San Diego. The U.S. Customs and Border Protection posted a video of the construction on Twitter.
The Trump administration hired the six companies to build eight prototypes, which cost up to $500,000 each. Half of the prototypes will be made of concrete, and the other half will be made of "other materials."
The walls are expected to range between 18 and 30 feet high. Once the prototypes are built, they will undergo a test by the Department of Homeland Security,
The construction of a border wall along the U.S. and Mexico border was one of President Trump's key campaign promises. MIT Technology Review estimated that the cost of the border wall would range up to $38 billion.