CNN  — 

Health and Human Services Secretary Alex Azar said Tuesday that his department was performing “one of the great acts of American generosity and charity” in its care of immigrant children.

Repeatedly pressed by CNN’s Wolf Blitzer on “The Situation Room” about why HHS won’t allow media cameras into facilities housing children, Azar said, “We have nothing to hide about how we operate these facilities.”

“It is one of the great acts of American generosity and charity, what we are doing for these unaccompanied kids who are smuggled into our country or come across illegally,” Azar added.

The Trump administration has faced international outcry since it implemented a “zero tolerance” immigration policy that resulted in thousands of undocumented families separated at the border, criticism that only intensified amid a snail’s pace of reunifying those families.

Physicians’ groups have criticized any practice of separating children from their parents as potentially causing lifelong damage.

In the interview, Azar praised the workers and facilities housing the children. The facilities mostly house children who came to the US by themselves, as well as children separated from parents at the border.

“These are groups of the most well-meaning, altruistic individuals,” he said. “These kids are happy, they are loved, they are cared for, it is a compassionate environment.”

Azar said HHS reunited fewer than half of the eligible separated migrant families in its care by a court-ordered deadline Tuesday because it is thoroughly reviewing each case to verify that parents are not dangerous and are actually the parents of the children in question.

“Our central mission is protecting child welfare while still reuniting families,” he said.

Azar dodged multiple questions from Blitzer about why the reunifications were taking so long, given that many of the children may have been in custody for months.

As of late Tuesday evening, 38 of 102 children identified for the deadline had been reunified with their parents, according to administration officials. Another 27 were determined to be ineligible for reunifications yet, and the remainder were awaiting family verification, background checks or for parents who have already been deported to be found.

The children who are addressed under the Tuesday deadline are all under age 5 and have been held by the government for weeks or months after being separated from their parents.

Tal Kopan contributed to this report.