COOLIDGE, Ariz. — Senior Trump administration officials visited southern Arizona on Wednesday to watch a demonstration of how parts of President Trump's border wall might be built.

The Department of Homeland Security’s top planning and project managers were on site at Fisher Industries, after the company said it has a method for building the wall that is cheaper than other proposals.

“We’ve come up with a system where we can build one mile per day,” Justin Murphy, general manager for Fisher Industries' sub-company Stinger Bridge and Iron, told DHS officials in a briefing.

The company says it could have a few hundred miles completed before the 2020 presidential election, when Republicans will be holding Trump’s feet to the fire on his biggest campaign promise: to build a wall.

Trump originally asked for $5.7 billion in December to build 234 miles of wall. Since Trump took office, about 1.5 miles of wall have been completed per month, and most of that is replacement wall, not in new areas. Hundreds of millions of dollars, roughly half of what DHS received each year, was spent on administrative and procurement costs.

Fisher said it can build all 234 miles for $1.4 billion. For another $3 billion, it will pave concrete roads the length of the wall and install lighting and technology on it. Funding from 2017 and 2018 has led to just 40 miles of completed wall, most of which replaced dilapidated structures.

Some Republican lawmakers, notably Sen. Kevin Kramer, R-N.D., have started to publicly criticize DHS for relying solely on the Army Corps of Engineers to build the wall. Kramer told DHS Secretary Kirstjen Nielsen earlier this month to fire the corps and look for other contractors.

The company was selected during a federal bid process in mid-2017 as of one of the eight wall prototype builders, and built a concrete wall.

In fall 2017, the prototype builders showed up in San Diego, Calif., to install their walls. Last July, Fisher inquired about making a bid to build the wall Trump wanted. The Trump administration told the company that the government decided to go with a steel, slatted fence.

The concrete prototype may have been a bust in terms of material, but the technique his team had used to install it had proven to be a game changer for erecting these types of trench-based structures. Other companies used cranes to install the barriers. Fisher arrived with a custom-made excavator from Caterpillar.

During Wednesday's demonstration, the company showed how it can plant the fence directly into the ground. While the Army Corps of Engineers has spent a few hours at a time using cranes to plant eight feet of wall at a time into the ground, Fisher’s excavator installed 56 feet of barrier in 30 minutes.

“It takes them 20 to 30 minutes after it’s picked up with the crane over to align it,” Murphy said. “We’re eliminating all the needs for cranes.”

The company is also addressing Democratic concerns by focusing on adding technology to the wall. Democrats have said they would rather rely on technology to monitor the border instead of erecting a physical barrier.

The process the company is proposing was demonstrated in front of 80 people Wednesday. In about two hours, 180 feet of fence was put in the ground and a portion of the ground adjacent to the wall was paved with concrete. Company officials then briefed DHS on the differences between Army Corps of Engineers’ current method and its process.

Grant Fisher, a vice president of Fisher Industries, said his company’s process requires four workers whereas the Army Corps’ uses dozens at a time, and has them stand in the trenches as thousands of pounds of steel is planted next to them.

The company is also offering a five-year warranty on the project.