SAN DIEGO – Amid an ongoing crisis at the southern border and in one of the hottest spots for migrant crossings, there remains a massive gap in the border wall – through which Border Patrol agents say illegal immigrants know to pour through.

Along the border near Otay Mountain, California, about a mile and a half from the port of entry in Otay Mesa, there remains an enormous gap in the double wall structure.

The Trump administration set up or bolstered two barriers, one right along the U.S.-Mexico border to deter illegal immigrants from crossing into the United States. The second is an additional wall, surrounded by roads and lights so that Border Patrol can scoop up and detain any crossers who manage to climb over or through the first structure.

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Border gap

This image shows the gap in the southern border in the San Diego sector. (Fox News)

But the Biden administration stopped the wall construction after entering office in 2021. While it has committed to completing some projects already funded by Congress, including repairing some gaps in the wall, this project in San Diego has remained incomplete.

"It has a very significant impact on operations because it's an open area where migrants can walk right into the United States unimpeded and when there's an influx of migrants, they just use that instead of climbing the fence and just walk in that open area," Manuel Bayon, president of the National Border Patrol Council in San Diego, told Fox News Digital in an interview.

Bayon described the gap as "frustrating" for agents.

Border wall

The Trump administration built a wall, along with roads and lighting, throughout the border area. (Fox News)

"It was almost completed. You're looking at possibly approximately two football fields. It’s just an open gap. It’s a beacon that here you're allowed to cross into the United States," he said.

The gap in the border wall represents the stark contrast between the policies of the prior Trump administration and the Biden administration. The Trump administration focused on increased interior enforcement and border wall construction. 

Border wall San Diego

This image shows the border wall separating Mexico from the U.S. in the San Diego Sector. (Fox News)

The Biden administration rolled back many of those measures, calling them ineffective. Instead, it has called for fundamental immigration reform and additional funding, while also emphasizing the importance of "root causes" of migration. 

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It has accused Republicans of failing to act for political purposes, including on a recent bipartisan Senate package. Republicans though, along with others including the Border Patrol union, have accused the Biden administration of fueling the crisis with its policies and have pointed to the record numbers of migrant encounters since the president took office. 

The administration has taken action, including a recent executive order designed to limit entries at the southern border when numbers are high. The White House said this week that since the order was announced, encounters have decreased by more than 50%, and the number of releases has decreased by 70%. Officials also say the administration has removed and returned more than 50,000 individuals to more than 100 countries, including by operating more than 175 international repatriation flights.

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"While the president’s action has led to significant results, it is clear that the only lasting solution to the challenges we are seeing on our border – the solution that would deliver additional authorities, resources, and personnel that we need to secure our border – is through congressional action," an official said.

Bayon, however, stressed that the union does not support the Biden administration due to what he said was a lack of enforcement, and also downplayed the importance of the executive order.

"It’s a Band-Aid on an open wound," he said.