Sen. Joni Ernst, R-Iowa, says border agents are concerned by the alarming number of young girls who are being "brutally" raped and assaulted by human smugglers as they trek across the southern border, and is demanding the Biden administration to take immediate action to stop these "heartbreaking" crimes.

Ernst detailed the "appalling" actions of cartel-backed "coyote" smugglers during an interview with Fox News Digital Tuesday. The senator traveled down to the Texas-Mexico border over the weekend with a delegation led by Sens. John Cornyn, R-Texas, Ted Cruz, R-Texas, Chuck Grassley, R-Iowa and other leading lawmakers.

Ernst said the senators were told that human smugglers and coyotes assisting the cartels are perpetuating these horrific crimes of sexual abuse toward over half of young girls as they make the journey, often unaccompanied, across the southern border to the U.S.

"The Border Patrol, they told us that about 30% of the women and girls that are being trafficked by the cartels up to the border are being sexually abused along the way. And those are just the ones that are reporting. And so the Border Patrol agents feel that 60% of them having been abused would be a more accurate number. So it really is appalling," Ernst told Fox News.

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Senators on McAllen, Texas, border with Mexico.

Senators on McAllen, Texas, border with Mexico. (Office of Senator Joni Ernst)

"And, you know, when we were there with just a few days earlier that a five and six-year-old girl had been just brutally raped right there at the border. And they said that they were so badly injured they had to call emergency medical personnel for the girls."

In addition, Ernst said agents told the senators about "rape trees" that are used by the criminal smugglers to abuse the girls.

"And we heard of what they call ‘rape trees,’ where there are areas where the cartel smugglers will take the women and girls and, well, rape them under a tree and then take their undergarments and throw them up into the tree and hang them from the branches," Ernst said border agents told her during the trip.

The smugglers know what they're doing which is "taunting the American law enforcement officials by doing this. It's in your face, look, we can do whatever we want and there will be no repercussions," stated Ernst. "It's so disgusting."

The smugglers know what they're doing which is "taunting the American law enforcement officials by doing this in your face. Look, we can do whatever we want and there will be no repercussions," stated Ernst.

The smugglers know what they're doing which is "taunting the American law enforcement officials by doing this in your face. Look, we can do whatever we want and there will be no repercussions," stated Ernst. (Office of Senator Joni Ernst)

When asked about what the border agents need in order to stop these crimes, the Iowa senator responded that it must start with the Biden administration ending its "open border" policy.

"[The border agents] said could make an impact is, one, change the policies that we have here in the United States. Catch and release is just an open border policy. And by having this open border policy, it encourages more people to traffic up to the border. More families will send their children to the border, and we know that they'll be abused along the way. And so we have to stop that. And they've said to stop the flow."

Ernst said that U.S. law enforcement must also start checking asylum claims more closely. 

Sen. Ernst traveled down to the Texas-Mexico border over the weekend with a delegation led by Sens. John Cornyn, R-Texas, Ted Cruz, R-Texas, Chuck Grassley, R-Iowa and other leading lawmakers.

Sen. Ernst traveled down to the Texas-Mexico border over the weekend with a delegation led by Sens. John Cornyn, R-Texas, Ted Cruz, R-Texas, Chuck Grassley, R-Iowa and other leading lawmakers. (Office of Senator Joni Ernst)

"So if we had different policies which wouldn't encourage people to come to the border, then we would have less people engaging in these dangerous activities, less moms and dads that are sending their children unaccompanied with these brutal, sadistic smugglers. You know, it's just so horrible. It's so much worse than I actually anticipated. And I knew it was bad. But hearing those stories, it's really heartbreaking," Ernst continued.

When asked if the White House had been informed about the information on young girls being sexually abused, Ernst responded that no one in the administration had reached out.

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"To my knowledge, no one from the administration has reached out to any members of our delegation to find out what we learned," the senator told Fox News Digital.

Ernst also spoke about the plight of two unrelated girls, one that was six years old and the other seven years old, who crossed the border unaccompanied from Honduras. U.S. Customs and Border Protection told the senators that after the girls arrived in the U.S., they went through the intake process and get delivered to their contact. But after agents follow up after 30 days, but there is no additional method for checking in on these children to ensure their safety.

"And even if they don't answer on that 30-day period check in, nobody follows up. How do we know that those children are actually going to a relative? How do we know that they are not being trafficked for sex use? How do we know they're not being sold into indentured servitude? I mean, I have so many questions about what the heck is going on. I'm guessing that many of those children go to relatives. But how do we know that?" Ernst questioned. 

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The senator also weighed in on remarks by Washington, D.C., Mayor Muriel Bowser this week that illegal migrants who entered Texas through the southern border who were bussed up to D.C. were "tricked" to get on the buses and moved out of the state.

"I did hear her comments and it is so laughable, I think whether it's the D.C. mayor or whether it's the White House press secretary," she said.

"The White House press secretary says that the border is secure. Well, if it is, we wouldn't have 1.7 million encounters already this year with people coming into the United States and to this is a sanctuary city, I think, where Bowser forgot that and people are not being tracked to coming to D.C. They're just being moved from point A to point B."