SAN ANTONIO — Despite all the talk of a border wall to curb illegal immigration, Trump administration officials and border security experts at this week's Border Security Expo agreed that it's just as important to fix legal loopholes that continue to draw immigrants north.

Department of Homeland Security Deputy Secretary Elaine Duke kicked off the first event Wednesday with a strong show of support for President Trump's campaign promise of a "big, beautiful wall" on the southwest border, but even she stressed the need for steps beyond the wall, including a more strict vetting of immigrants.

Every one of the two dozen Customs and Border Protection, Border Patrol, and Immigration and Customs Enforcement workers that spoke with the Washington Examiner this week agreed with DHS leadership that the wall was a critical physical step to improving national security.

But where Trump has focused on lowering illegal immigration by building a wall, DHS employees at the event offered a number of additional, nonphysical ways to deter it, including reforming the Trafficking Victims Protection Reauthorization Act, changing asylum standards, doing away with sanctuary cities, and legislating local law enforcement to cooperate with ICE detainer requests.

"The billions of dollars we spend on law enforcement means nothing because you chose to have a U.S. citizen child while you knew you were in the country illegally. If that’s the message that you want to continue to send ... you are never going to fix the southwest border," said acting ICE Director Thomas Homan.

"Sanctuary cities, end them. Detainers, legislate them. TVPRA, change it. Asylum, raise the bar. We have the knowledge to fix it, but you know what we need is the willpower of Congress," he added. "I've been doing this 34 years; we’re talking about the same thing every year."

CBP Deputy Commissioner Ronald Vitiello said Thursday ambiguities in immigration law must be reformed, or those who know of the loopholes will continue to show up at the southwest border and claim asylum as the current upward trend in border statistics indicates.

"What we’re seeing in the populations is if you come as a family unit or an unaccompanied minor, the way the policy loopholes and the legal framework is set up [is so] that we turn these folks over to ICE and in the case of unaccompanied minors, through ICE to HHS [Health and Human Services]. They’re eventually released into our communities, and so that encourages others to come," Vitiello told reporters. "You’ll remember in 2014, the department was overwhelmed by unaccompanied children and family units. Those legal frameworks exist today, and that trend is coming back."

Since the spring, the number of inadmissible people along the southwest border has increased each month. In addition, the number of family units containing at least one adult and one minor and unaccompanied minors on their own have skyrocketed since the fall. In October, 4,939 family units were apprehended, CBP data shows. In November, that number jumped to more than 7,000 and then up to 8,121 in December.

Unaccompanied minor apprehensions have also ticked up from a little more than 3,100 in October to topping 4,000 in December.

Vitiello said part of the problem is due to the TVPRA, which mandates any minor from a noncontiguous country who arrives at the U.S. border must receive special due process to ensure he or she was not trafficked.

Family units are also guaranteed certain protections and are supposed to go through immigration courts to prove they are related and fled to the U.S. with legitimate reason.

A 2014 report found 90 percent of migrants who were released into the interior of the U.S. while they waited court dates never showed up.

"If we apprehend people at the border, we need a way to remove them there ... Being able to remove people after their due process in a quick and rapid manner, that’s what we’d like to see," Vitiello added.

One of DHS Secretary Kirstjen Nielsen's goals has been changing asylum standards. However, the White House's new four-point immigration reform framework did not include Nielsen's requests. Vitiello did not address a reporter's question on Thursday over whether Nielsen was unhappy with that move.

"Like the TVPRA, there are questions about the credible fear standard and how people request asylum," he said. "We’re going to watch that very closely."

Homan's greatest concern was sanctuary cities and how they prevent law enforcement from carrying out removal orders, and give criminal illegal immigrants in those cities protection from being deported.

"The more they hear about sanctuary cities, the more they’re saying, ‘Look, if we get into the country illegally, get by the Border Patrol, or even get caught by the Border Patrol,'" he said. "When you’re going to your proceedings, you get released from your detention, the thought of getting to a sanctuary city, like get to San Francisco, you can even get arrested for committing a crime and they’re not going to work with ICE and they’re going to help shield you from federal law enforcement. That’s a huge selling factor for someone who wants to come to this country illegally."

DHS officials did not criticize Trump's immigration framework of border security, ending the diversity visa lottery, reforming "chain migration" policies, and providing a pathway to citizenship for up to 1.8 million eligible illegal immigrants, but said there is much more work to be done countering illegal immigration.