Republican Rep. Will Hurd, who represents more of the southern border than anyone in the House of Representatives, has emerged as one of the most vocal critics of President Donald Trump's plan to build a wall along the US-Mexico border.

Hurd represents Texas' 23rd Congressional District, which stretches roughly 820 miles from El Paso to San Antonio.

Hurd, a former undercover CIA agent, has been pushing for what he has referred to as a "smart border wall," or a technology-based approach.

On Wednesday, the Texas congressman told CNN, "I think building a concrete structure sea to shining sea is the most expensive and least effective way to do border security."

Republican Rep. Will Hurd, who represents more of the southern border than any of his colleagues in the House of Representatives, has emerged as one of the most vocal critics of President Donald Trump's plan to build a wall along the US-Mexico border.

Hurd represents Texas' 23rd Congressional District, which stretches roughly 820 miles from El Paso to San Antonio.

He has repeatedly stated that he is not in favor of Trump's wall and narrowly won reelection in the 2018 midterm elections in part by campaigning against the president's plan.

"I think building a concrete structure sea to shining sea is the most expensive and least effective way to do border security," the Texas congressman told CNN, on Wednesday.

Sections of the border spanning across California, Arizona, and New Mexico are largely already covered with physical barriers. If Trump's proposed wall (or barrier) is constructed on the southern border, much of it will occur in Hurd's district.

Building along the Texas border would be complicated. Not only does the border not run in a straight line, but the territory it falls on is hardly ideal for building due to the terrain. Additionally, land owned by Hurd's constituents would likely be needed for the project to be feasible, which is part of the reason he opposes the wall. The location also includes Big Bend National Park.

Read more: Several House Republicans broke with Trump and voted with Democrats to pass 2 bills that would end the government shutdown

"Property rights are important to all Americans — especially Texans — and most of the property along our border has been privately held for generation," Hurd told The Atlantic in April 2017. "Many Texans I speak to think there are better ways to achieve border security without taking their lands, so you can expect a lengthy and expensive fight from these folks."

Hurd, a former undercover CIA agent who's also the only black Republican currently in the House of Representatives, has been pushing for what he's referred to as a "smart border wall." What he's calling for is a technology-based approach to border security that would involve drones and other forms of surveillance to help stop people from crossing into the US from Mexico illegally.

"We have driverless vehicles, we can use facial recognition software as payment for goods, and outer space is the next hot commercial travel destination. Yet we continue to debate the efficacy of a third century solution to secure our nation’s southern border," Hurd wrote in an August 2017 op-ed for USA Today.

"What we need is a 'Smart Wall' to solve our 21st century border problems," Hurd added. "A Smart Wall would use sensor, radar and surveillance technologies to detect and track incursions across our border so we can deploy efficiently our most important resource, the men and women of Border Patrol, to perform the most difficult task — interdiction."

Read more: Trump gave his border security speech with a photo of his impoverished, immigrant Scottish mother behind him

Trump's fight with Democrats over obtaining funding for the border wall has led to a partial government shutdown that has now lasted over two weeks. Last week, the president said drones and sensors could be helpful in terms of protecting the border, but contended they wouldn't go far enough.

Trump made the wall a cornerstone of his 2016 presidential campaign (and claimed that Mexico would pay for it). However, Congress is being asked for appropriations fo the barrier, and there are conflicting estimates on how much the president's proposed border wall would cost, ranging from $21.6 billion to $70 billion. Many experts have contended Trump's wall would be an inadequate means of addressing the complex array of issues associated with immigration in the US.

Read more: Trump's insistence on a border wall ignores the fact roughly half of all undocumented immigrants entered the country legally

The president on Tuesday gave a speech in the Oval Office in an effort to convince the American public to support his plan, offering a number of falsehoods and misleading claims in the process.

Trump has referred to what's happening at the border as a "crisis," but hasn't declared a national emergency, despite previous reports that he was considering it.

Meanwhile, the government shutdown persists and it is on track to be the longest in US history. Roughly 800,000 federal workers have been impacted, some are furloughed, while others who are deemed "essential" are working without pay.

Hurd on Tuesday night rebuked Trump and called for an end to the government shutdown.

"If this is a crisis, the people that are dealing with this crisis should get paid," the Republican congressman told CNN.

Recent polls have shown most Americans blame Trump for the shutdown and oppose his proposal for a border wall.

In December, Trump said he would be "proud" to take responsibility for a government shutdown in order to obtain funding for his border wall, but he has since placed blame on Democrats in Congress.

A Wednesday meeting between Trump and Democratic ended when the president reportedly stormed out of the room after House Speaker Nancy Pelosi said no to funding a wall or steel barrier.