The Trump administration is moving ahead with constructing designs for a wall along the U.S.-Mexico border.

The Department of Homeland Security recently awarded eight total contracts for prototypes to be built within the coming months. U.S. Customs and Border Protection issued awards for 30-foot-tall concrete prototypes and designs made out of other materials.

While President Donald Trump and Congress are still negotiating ways to fund a border wall—a signature campaign promise of the president—the administration is moving forward with existing funds to test designs for the wall.

"Congress approved DHS and CBP to reprogram $20 million to commence wall planning and to award the construction of four to eight prototypes," a DHS spokesperson told the Washington Free Beacon. "Planning includes use of U.S. Army Corps of Engineers and architecture and engineering support for real estate, environmental, and wall design efforts."

The funds were reprogrammed from existing funding from fiscal year 2017.

The two contracts have been in the works since March. Trump signed an executive order during his first week in office directing DHS to "immediately plan, design and construct a physical wall along the southern border, using appropriate materials and technology to most effectively achieve complete operational control of the southern border."

Six companies received contracts for wall prototypes. Caddell Construction, and W.G. Yates and Sons Construction Company each received contracts to build both a concrete model and one made out of other materials.

Companies also receiving contracts include Fisher Industries, Texas Sterling Construction Company, KWR Construction, Inc., and ELTA North America Inc.

Caddell Construction, based in Montgomery, Ala., has contracted with numerous federal agencies and previously was tasked to build the U.S. embassies in Beijing and Kabul, two terminals at the George Bush International Airport in Houston, and the "Patton" Command and Control Headquarters Complex at Shaw Air Force Base in South Carolina.

ELTA North America specializes as an electronic systems defense contractor and has developed long-range antiballistic missile radar systems, surveillance radar, and intelligence, surveillance, and reconnaissance vehicles.

Texas Sterling, based in Houston, builds highways, bridges, and airports. Yates Construction has built manufacturing plants and a power operations center in Mississippi and most recently the Springhill Suites by Marriott in Atlanta.

The companies must first determine a start date for construction. After a start date is agreed to, each company will have 30 days to complete the prototype.

The concrete walls will be up to 30 feet high. Other designs will be considered for different parts of the geologically diverse border.

"First, given their robust physical characteristics—for example, they will be between 18 and 30 feet high—the ‘other materials' border wall prototypes are designed to deter illegal crossings in the area in which they are constructed," the CBP said. "Second, they will provide an innovative perspective in the application of new materials which will allow CBP to evaluate the potential for new wall and barrier designs to complement the current wall and barrier used along the Southwest border."

The Border Patrol will then evaluate the prototypes once they are completed.

"The prototypes will inform future design standards which will likely continue to evolve to meet the U.S. Border Patrol’s requirements," the CBP said. "Through the prototyping process, CBP may identify new designs or influences that will expand the current border barrier toolkit, which is based on U.S. Border Patrol requirements, that CBP could use to construct a border wall system."