EXCLUSIVE – Acting Homeland Security Secretary Chad Wolf, in an exclusive interview with Fox News while touring the border just days after taking the helm at DHS, detailed what he described as an urgent and “exciting” plan to go after the gangs fueling the flow of illegal migrants, weapons and drugs across the southern border.

"The TCOs and cartels, they control the southern side of the border — they have to be paid, they have to be compensated for any of these large flows coming across the border,” he told Fox News. “You eliminate that and you eliminate their ability to recruit in Central America and bring these folks up.”

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"TCO" refers to transnational criminal organizations, a term covering both the murderous drug-running cartels that have plagued Mexico as well as other gangs responsible for smuggling operations at the border. The Trump administration has prioritized going after these organizations, last year labeling groups ranging from MS-13 to the Sinaloa Cartel as top TCO threats.

Wolf's warning hinted that the new secretary, among other tactics, intends to go after the gangs’ cash flow.

While Wolf doesn't think that the issue of TCOs had been ignored previously, he says the fight is going to need more resources from the government. He also noted that issues that his predecessor Kevin McAleenan had pushed, such as the fight against so-called child recycling at the border, were part of that battle against the gangs and cartels.

“So when we talk about TCOs, it’s not only them facilitating the flow of migrants to the border, it’s also drugs, weapons and a lot of the violence,” he said. “So targeting TCOs in a real way … is something that I will certainly push and work on from a DHS perspective, but we’ll also be working in the larger interagency to really start targeting these groups, because once you start eliminating their ability to bring migrants and the like, then I think you’ll start seeing a different dynamic.”

Wolf spoke to Fox News in his first sit-down interview since taking over DHS for McAleenan this month. He spoke during a visit to the Texas-Mexico border where he toured migrant detention centers, surveyed wall construction and spoke to agents on the ground dealing with the migrant crisis first-hand.

"The department already has a number resources dedicated to that, I think we can do more, we are doing more and I think the U.S. government overall can do more and that’s the exciting part of this job,” he said.

Wolf’s appointment comes at a crucial time for the administration. After facing an unprecedented migrant crisis at the border earlier in the year, the administration has taken a series of measures to stem the flow – pushing through numerous asylum reforms, ramping up border wall construction, and striking deals with countries south of the border to overhaul where asylum seekers are processed.

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The most significant of those is the expansion of the Migrant Protection Protocols (MPP), known as the “Remain-in-Mexico” policy, which sends migrants back to Mexico while they await their immigration hearings. The expansion of that policy over the summer has coincided with a dramatic drop in migrant apprehensions – nearly 70 percent since May -- although the administration concedes that number is still too high.

“The importance of MPP can’t be stated enough, it is what’s allowed us to take control of the crisis that we saw in April and May. The idea is to make sure we process individuals in a timely manner but make sure they wait south of the border,” he said.

But that program faces a legal challenge at the traditionally liberal Ninth Circuit Court of Appeals, where a ruling is expected within the next few weeks. The court could uphold the program’s legality, demand some minor changes or shut it down. Wolf warns that the latter could have a dire effect on the U.S. effort to regain control of its southern border.

“So you get an adverse ruling on MPP and it’s going to make the job of the men and women of Border Patrol as well as [Customs and Border Protection] and [Immigration and Customs Enforcement] ... very difficult for them, so it really can’t be overstated how much the program means to the department in controlling the crisis,” he said.

He cited MPP and the international agreements with other countries such as Guatemala – where migrants last week started to be flown for asylum claims – as “critically important," along with President Trump’s own involvement in negotiations with Mexico.

“So I like to think of them as a chorus of programs that have really driven down those numbers; take away any one of those and it’s going to have a huge impact,” he said.

Even beyond the court ruling, officials are only cautiously optimistic about the cooperation with those countries beyond the near future. Wolf said he would never call himself confident about actions that are out of U.S. control

“We like what we see, but we monitor that on a day by day, week by week, month by month basis, so we need to continue to see that progress,” he said in terms of cooperation with Mexico. “We share a lot of intelligence, we share a lot of information between the two countries and as long as they continue to take action to control the folks that are arriving at the southern border, I think we’ll be in a good place.”

Wolf, a former chief of staff to former Secretary Kirstjen Nielsen, was not initially on many observers' lists to take over from McAleenan – with many predicting that firebrands Ken Cuccinelli (now the acting deputy) or CBP Acting Commissioner Mark Morgan would take the spot instead.

Wolf has been controversial with some on the right and on the left. Immigration hawks expressed concern about not only his links to Nielsen – whom they have seen as not tough enough on immigration – but also his past as a lobbyist for companies advocating for the H1-B visa program.

Meanwhile, many on the left were also furious with Wolf’s appointment, drawing a link between his time as chief of staff and controversial policies such as the travel ban and the separation of children from their accompanying adults.

“By confirming Chad Wolf, the @SenateGOP has rewarded a man who has stood by @realDonaldTrump’s most immoral and anti-American policies: family separation, the Muslim ban, and the unlawful national emergency declaration,” Rep. Veronica Escobar, D-Texas, tweeted this month. “He should have no place in our government.”

But Wolf says those criticisms from the left largely arise from misunderstandings.

“It’s a fundamental misunderstanding of my job as chief of staff and what I did,” he said. “That seems to indicate that I controlled all 240,000 people at this department, when in fact that’s not reality.”

“I think they just picked the closest person to the person they don’t like, in this case Secretary Nielsen, and decided ‘well, it’s an easy target.’”

The same goes, he says, for criticism about his lobbyist past from hawkish groups – which he says he will be meeting with in the coming weeks.

“Take, actually, a look at the work I did for the private sector, it aligns with the president’s agenda when it comes to what we’re trying to do on protecting workers and rooting out a lot of the fraud and abuse in a lot of the guest worker program,” he said. “So I’ll have a chance to talk to them, I’ve talked a little a bit already, we’ll clear that up and I don’t see that being a big issue going forward.”

As for what’s next, Wolf says he wants to continue the administration’s current approach – and is keen to keep Congress’ feet to the fire on getting measures passed that help control the border. In addition to more funding for CBP and ICE, DHS wants Congress to pass three legislative changes: a change to the Flores settlement that limits how long minors can be kept in custody; an increase of the initial “credible fear” standard for asylum cases; and a fix that allows unaccompanied children from Central America to be treated the same as those from Mexico.

Overall, the Wolf DHS appears set to keep the administration’s hard-line on illegal immigration, and continue those policies that have seen apprehensions drop in recent months – despite the fierce criticisms coming from Democrats and immigrant advocacy groups.

“So we’ll continue to look at MPP, we’ll continue to look at international agreements we have, try and do more with Mexico and the like,” he said. “And there are some other programs the department is looking at to help manage that crisis, root out that fraud in the asylum system that I think we all acknowledge is there, and to make sure those folks that need the protection get the protection, and those that don’t, don't remain in the U.S. -- that if they have no legal right to be here, then they shouldn’t be here.”