A top Department of Health and Human Services official said Thursday he would never support a policy that separates families at the border.

“Neither I nor any career person in [HHS’ refugee resettlement office] would ever have supported such a policy proposal,” Commander Jonathan White told Rep. Brett Guthrie, R-Ky.

.@RepGuthrie (R-KY): Would you have advised DOJ or DHS to implement the "zero-tolerance" immigration policy? HHS official Cmdr. Jonathan White: "Neither I nor any career person in [the Office of Refugee Resettlement] would ever have supported such a policy proposal." pic.twitter.com/xqe7FIXlxl — PBS NewsHour (@NewsHour) February 7, 2019

White’s disavowal came amid a series of questions from lawmakers on the House Energy and Commerce subcommittee in a hearing on HHS’s role before and after the Trump administration officially rolled out its “zero tolerance” policy last year that resulted in the separation of at least 2,700 migrant families — possibly many more.

The policy didn’t originate at HHS, which was charged with caring for the children after they were separated from their parents. Rep. Diana DeGette, D-Colo., said in the hearing that that fact “doesn’t relieve the department from answering some key questions,” such as whether HHS officials did anything to stop the “zero tolerance” policy and whether they raised concerns about the harm it could inflict on the children.

Thursday’s hearing is the first of three scheduled in the coming weeks that will seek to uncover more answers as to when and how the widely condemned policy was discussed and implemented within the government, and how the effects of that policy are still being felt months after being halted by an executive order. The hearing comes amid heightened concerns over whether the government will ever know the true number of separated families.

White, who is part of HHS’s U.S. Public Health Service Commissioner Corps, has overseen the federal government’s court-ordered efforts to reunite separated children with their parents.

White previously served as the deputy director of the department’s Office of Refugee Resettlement’s Unaccompanied Alien Children’s (UAC) program. Throughout Thursday’s hearing, White repeated that he, along with other colleagues, had raised concerns to department leadership multiple times before the policy was implemented. That includes Scott Lloyd, director of the Office of Refugee Resettlement, Steven Wagner, an acting assistant secretary at HHS, and Maggie Wynne, counselor to the secretary for HHS

Responding to Guthrie’s questions, White said the first meeting he attended on the topic of “zero tolerance” happened on Feb. 14, 2017, a few weeks after President Donald Trump took office. That’s when the idea came up of referring migrant children who entered the U.S. with parents as to HHS’s Office of Refugee Resettlement. After children were separated, the government would deem them “unaccompanied alien children,” a designation that’s usually reserved for migrant children who arrive at the border alone.

After that meeting, where officials from the Justice Department, the U.S. Customs and Border Protection, and U.S. Immigration and Customs Enforcement were also in attendance, White said he shared the policy option discussion with his own leadership.

“And on a number of occasions, I and my colleagues made recommendations, raising concerns not only about what that would mean for children, but also what it would mean for the capacity of the program,” he said.

White, who has since changed roles at HHS, also said he was advised that no policy would result in family separations by agency officials. “And that remained the answer I received during my entire tenure,” he said.

Here are three additional takeaways from the hearing:

When HHS first heard about the “zero tolerance” policy

White testified that HHS did participate in discussions about a potential policy that would result in family separations, but that neither he nor his colleagues were notified of a formal policy before it was implemented.

“I was aware of the formal policy notification when the [former Attorney General Jeff Sessions] said it on television, on April 6,” White told lawmakers.

The total recorded number of separated migrant families: “unknown”

A 24-page watchdog report released in January said there may be “thousands” more migrant children who were separated from their parents than the government previously recorded.

Ann Maxwell of the HHS Office of the Inspector General, the office that wrote the report, reiterated at the hearing some of findings from January, including that the exact number of separated children is “unknown.” She said in her prepared testimony that HHS officials think there could be thousands of more separated children who were released from the agency’s refugee resettlement office — those who aren’t currently counted by the ongoing lawsuit over family separations.

As to how this could happen, she said part of the explanation is that there was no integrated data system that consistently tracked who was separated by DHS agents and then transported to HHS care.

Maxwell also said the agency has received more separated children since the June court order that forced the government to reunite the migrant families. DHS has cited concerns over parents’ criminal histories as being the impetus for some of these separations, but the agency has provided “limited information,” she added.

Two back-to-back questions posed by Rep. Jan Schakowsky, D-Ill., were met with silence from the panel of government officials, who did not immediately respond to her queries about how many people were affected by the policy.

"Can anybody here, on this panel, challenge this: The United States does not know how many children have been separated from their parents?" @janschakowsky asks. After no answer, she asks, "Does anyone know how many are still separated from their parents? … Nobody knows." pic.twitter.com/PL0UeMIpfk — PBS NewsHour (@NewsHour) February 7, 2019

“Can anybody here on this panel challenge this? The U.S. does not know how many children have been separated from their parents,” the congresswoman asked.

The panel was silent. “No one,” she said after a couple of beats.

“Does anyone know how many are still separated from their parents?”

After another beat, Schakowsky said, “Nobody knows.”

After calling the situation surrounding these separations “irresponsible” and “sloppy,” Schakowsky called what happened “state-sponsored child abuse, and I would go as far as to say kidnapping of children,” she said.

How separations cause trauma

Toxic stress for children who undergo a trauma — like being separated from their parents — is an “accepted scientific reality,” White told Rep. Raul Ruiz, D-Calif., during the second part of the panel, when medical professionals and advocacy groups spoke to the harmful consequences for children’s behavioral and physical health. Potential effects include stunted brain development or making children more vulnerable to chronic illnesses.

"The consequences of separation for many children will be lifelong," HHS official Cmdr. Jonathan White told @CongressmanRuiz at today's @EnergyCommerce subcommittee hearing on the Trump administration's "zero-tolerance" immigration policy. pic.twitter.com/lJU5y6BVke — PBS NewsHour (@NewsHour) February 7, 2019

“So this problem is not over even after they reunify the child with the family, right?” Ruiz asked.

“The consequences of separation for many children will be lifelong,” White said.

“Decades of psychological research have determined that it is in the best interest of the child and the parents to keep families together,” Dr. Cristina Muñiz de la Peña said in her prepared testimony on behalf of the American Psychological Association.

Peña, mental health director for the Terra Firma Immigrant Youth Clinic in New York, wrote of how a “total lack of control and terror” during one separation left a 16-year-old Honduran girl “with severe helplessness, which she described as feeling like … her life would never get better.”

Peña, among others who testified today, pointed to research showing that the longer the separation occurs, the worse the effects could be for children.

White has previously testified to Congress about the “significant potential for traumatic psychological injury to the child” involved in separating children from parents. Back in July, he told a a Senate hearing that the Trump administration was warned about implementing “any policy” that led to family separations because the consequences could be harmful to children.

“There’s no question,” White said.