Washington (CNN) A senior Trump administration official on Tuesday stood by his controversial comments comparing the detention centers for immigrant families to "summer camp," but declined to answer whether he'd send his own children there.

The remarks came at a congressional hearing where immigration and border security officials struggled to answer foundational questions from senators about the administration's push to expand the detention of immigrant families and children.

Democratic Sen. Kamala Harris of California asked Immigration and Customs Enforcement's chief of arrests and deportations, Matthew Albence, if he stood by his comments earlier this summer that family detention centers are like "summer camp."

"Absolutely I do," he said.

But he demurred when asked whether he'd send his own children, or those of people he is close to, to the centers.

"Would you send your children to one of these detention centers?" she asked.

"That question's not applicable," he said.

Albence did say the standards for family centers are "very safe" and "humane," and that at one he had visited, families had access to TVs, food and video games and other activities.

"The point is, the parent made the illegal entry," Albence said when pressed further. "The parent put themselves in this position."

The Senate Homeland Security and Governmental Affairs Committee hearing topic was ostensibly a court settlement that governs how immigrant children can be treated by the US, including limiting the length of time a family can be involuntarily detained to 20 days. The administration is seeking to nullify that settlement and allow itself to detain far more immigrant families for far longer.

Harris' line of questioning was one of a series from Democrats, who pressed the officials on why they'd want to expand family detention and child detention despite widely held beliefs among medical professionals that even short periods of detention can inflict permanent and devastating trauma on children . Though the hearing did not include the Department of Health and Human Services, which runs the government's program for immigrant children who are in the US on their own, senators also asked about the ongoing fallout over family separations and unaccompanied child detention.

Members of both parties pressed as to why the agencies were not pursuing other measures with bipartisan support that could streamline the immigration court system over an expensive effort to vastly expand family detention.

Investigating child abuse

Sen. Heidi Heitkamp, a North Dakota Democrat, focused on reports of sexual assault and abuse at child detention facilities, asking each agency's official whose responsibility it was to investigate those allegations. The representatives from ICE and the Justice Department demurred.

Asked if it would be a federal crime in that it happened in a federal facility, acting Deputy Assistant Attorney General Joseph Edlow said he couldn't answer that.

Edlow said that in general he deferred to the Department of Homeland Security and HHS on allegations of abuse.

Similarly, Albence said only that he was "not aware of any" accusations of sexual assault in family detention centers, which are run by ICE.

Customs and Border Protection acting Deputy Commissioner Robert Perez did say his agency "vigorously" investigates claims of misconduct, but said it's a "relatively small" amount of instances compared with the overall actions of his agency's officials, who go "over and above."

Heitkamp called it "disturbing" that the Justice Department couldn't even weigh in on whether it was a federal crime.

Edlow then added that if a case is referred to a US attorney's office for prosecution, "based on those facts, the US attorney's office will make the determination whether prosecution is appropriate."

Trauma to children

The officials also said they were not familiar with medical professionals' assessments that detention is harmful to children, nor could they say whether the administration had weighed that in its policy development.

Democratic Sen. Maggie Hassan of New Hampshire asked Albence and Perez if they were aware of a report from the American Academy of Pediatrics that "even brief detention can cause psychological trauma and induce long-term mental health risks for children."

Albence said he had only "seen media reports" about it; Perez said he was not aware of it.

Both officials also said they were not familiar with a whistleblower letter from the DHS's own medical professionals that concluded there's a high risk to children in detention that "no amount of programming can ameliorate."

Earlier, Democratic Sen. Gary Peters of Michigan had asked about similar research and whether it was considered in developing the proposal to expand detention. Albence said he wasn't involved in the writing of that proposal, though the process was "very extensive" and detention centers are "humane."

"How long is too long, do you think, to detain a child in a detention facility?" Peters asked.

"I'm certainly not qualified to answer that question, sir," Albence said.

Hassan asked why, given all of the research, their agencies support nullifying the court settlement that caps detention of families.

Perez said the goal was deterring families from coming to the US.

"From CBP's perspective, the modification of the Flores agreement is more so a deterrence and the ability to help deter a myriad of pull factors (for immigrants)," Perez said, as the officials explained that the administration thinks immigrants are attracted to the US because they believe families get a free pass into the country.

Pressed on other options

Both Democrats and Republicans on the panel pressed the officials about other options to deal with inefficiencies in the immigration system besides expanding family detention, including bipartisan support for substantially increasing the resources of the immigration courts to hear cases and move them more quickly.

They also asked about alternatives to detention, like electronic monitoring, and immigrants' access to lawyers.

"Wouldn't this be a better investment than building family prisons?" Sen. Claire McCaskill of Missouri, the top Democrat on the committee, asked rhetorically.