WATCH: Sen. Hawley slams DHS Secretary Mayorkas on border response: ‘You’re responsible’

"Here's the problem. Every time before you come before this committee you always say, 'It's going to get better. Our plan is going to work at some future point.' And you also usually say 'It's really not as bad as it looks.' And then every time you leave, it gets worse and worse," Hawley told Mayorkas.

"This is a humanitarian crisis in Del Rio. You can spin it whichever way that you want but you're quite right: We should not minimize the humanitarian conditions for which, frankly, you're responsible. You and your administration are responsible," Hawley continued.

In both July and August, the number of people encountered by Customs and Border Patrol agents crossing the border illegally surpassed 200,000 each month, marking a huge jump, over 150,000 more people each month than the last surge in migration experienced in 2019.

Over the past week, Haitian migrants began gathering under the International Bridge in Del Rio, Texas, stuck there as immigration facilities nearby were overcrowded. Over the weekend, the Border Patrol moved to get these migrants either into custody for processing, or sent back to their countries of origin. At one point, around 15,000 people were gathered under this bridge, crossing freely back into Mexico for supply runs.

According to the New York Post, "The DHS secretary said he didn't have Tuesday's numbers but said there were fewer than 10,000 Haitians."

"Tens of thousands of people living in conditions that are startling, startling, brought here because of your policies," said Hawley. "Let me give you an example. The Washington Post reported on Sunday that one Haitian woman said that she and her family decided to travel from Chile where she was residing to Del Rio because they heard 'President Biden was letting people in.'"

"And of course you've offered this temporary protective status to Haitians illegally residing in the United States starting in May, then you halted deportation flights earlier this summer," he noted. "Don't you think that you bear responsibility for this latest crisis?" Hawley questioned.

Addressing the nation on Tuesday, Mayorkas stressed that "any mistreatment or abuse of a migrant is unacceptable, is against Border Patrol policy, training, and our department's values."

"Indeed, we have a directed investigation. That investigation is underway, and it will be conducted swiftly, and the public needs and deserves to know its results. I also have directed the Office of Professional Responsibility be on site in Del Rio full time. We will not tolerate any mistreatment of an individual," said Mayorkas.