Four companies were awarded contracts to build reinforced concrete models up to 30 feet (nine meters) high, Acting CBP Deputy Commissioner Ronald Vitiello announced. 

The prototypes have to have “anti-climb” features to deter illegal immigrants from sneaking into the United States.

The government also expects to award contracts for non-concrete prototypes.

They will be evaluated not only on the physical structure, but “all of the tools that help us secure the border,” he said.

Trump promised in his election campaign last year to build a wall to keep out illegal immigrants. For the fiscal 2018 budget, the government has proposed $1.8 billion to begin building what could become a $20 billion project spanning the 3,200-kilometer (2,000-mile) frontier.

But Congress is deeply split over the budget and worries are that it might not be able to bridge its differences and fund the government before the fiscal year begins on October 1. 

On Sunday Trump insisted that Congress must find a way to pay for his promised border wall, branding Mexico a hotbed of violent crime.

And he has warned that he will close down the government if Congress does not give him funding for the wall. DM