PHOTO: CNN
Now playing
01:34
Trump official: Separations are saving lives
PHOTO: CNN
Now playing
01:23
Senator: Family separation is kidnapping
SAN DIEGO, CA - JULY 16:  An American flag flies along a section of the U.S.-Mexico border fence on July 16, 2018 in San Diego, California. The entire Southwest border saw 34,114 U.S. Border Patrol apprehensions in the month of June compared with 40,338 in May.  (Photo by Mario Tama/Getty Images)
SAN DIEGO, CA - JULY 16: An American flag flies along a section of the U.S.-Mexico border fence on July 16, 2018 in San Diego, California. The entire Southwest border saw 34,114 U.S. Border Patrol apprehensions in the month of June compared with 40,338 in May. (Photo by Mario Tama/Getty Images)
PHOTO: Mario Tama/Getty Images North America/Getty Images
Now playing
03:57
Hear: Immigrant moms plead with judge for kids
U.S. Border Patrol agents take a father and son from Honduras into custody near the U.S.-Mexico border on June 12, 2018 near Mission, Texas. The asylum seekers were then sent to a U.S. Customs and Border Protection (CBP) processing center for possible separation. U.S. border authorities are executing the Trump administration
U.S. Border Patrol agents take a father and son from Honduras into custody near the U.S.-Mexico border on June 12, 2018 near Mission, Texas. The asylum seekers were then sent to a U.S. Customs and Border Protection (CBP) processing center for possible separation. U.S. border authorities are executing the Trump administration's zero tolerance policy towards undocumented immigrants. U.S. Attorney General Jeff Sessions also said that domestic and gang violence in immigrants' country of origin would no longer qualify them for political-asylum status. John Moore/Getty Images
PHOTO: John Moore/Getty Images
Now playing
01:26
Parents of 71 children still unidentified
Now playing
01:48
You heard her cry for her mom. See their reunion
PHOTO: CNN
Now playing
01:34
Trump official: Separations are saving lives
PHOTO: Emanuella Grinberg/CNN
Now playing
03:16
Watch daughter wait for separated mom's arrival
U.S. Border Patrol agents take a father and son from Honduras into custody near the U.S.-Mexico border on June 12, 2018 near Mission, Texas. The asylum seekers were then sent to a U.S. Customs and Border Protection (CBP) processing center for possible separation. U.S. border authorities are executing the Trump administration
U.S. Border Patrol agents take a father and son from Honduras into custody near the U.S.-Mexico border on June 12, 2018 near Mission, Texas. The asylum seekers were then sent to a U.S. Customs and Border Protection (CBP) processing center for possible separation. U.S. border authorities are executing the Trump administration's zero tolerance policy towards undocumented immigrants. U.S. Attorney General Jeff Sessions also said that domestic and gang violence in immigrants' country of origin would no longer qualify them for political-asylum status. John Moore/Getty Images
PHOTO: John Moore/Getty Images
Now playing
00:57
Most toddlers still separated from families
Young migrant children, whose faces can not be shown, are seen at the US Customs and Border Protection Facility in Tucson, Arizona during a visit by US First Lady Melania Trump, June 28, 2018. (Photo by MANDEL NGAN / AFP)        (Photo credit should read MANDEL NGAN/AFP/Getty Images)
Young migrant children, whose faces can not be shown, are seen at the US Customs and Border Protection Facility in Tucson, Arizona during a visit by US First Lady Melania Trump, June 28, 2018. (Photo by MANDEL NGAN / AFP) (Photo credit should read MANDEL NGAN/AFP/Getty Images)
PHOTO: MANDEL NGAN/AFP/AFP/Getty Images
Now playing
01:44
Only 54 children to be reunited by deadline
BROWNSVILLE, TX - JUNE 22:  A crying  Honduran woman and her child wait along the border bridge after being denied into the Texas city of Brownsville which has become dependent on the daily crossing into and out of Mexico on June 22, 2018 in Brownsville, Texas. Immigration has once again been put in the spotlight as Democrats and Republicans spar over the detention of children and families seeking asylum at the border. Before President Donald Trump signed an executive order Wednesday that halts the practice of separating families who were seeking asylum, over 2,300 immigrant children had been separated from their parents in the  zero-tolerance policy for border crossers.  (Photo by Spencer Platt/Getty Images)
BROWNSVILLE, TX - JUNE 22: A crying Honduran woman and her child wait along the border bridge after being denied into the Texas city of Brownsville which has become dependent on the daily crossing into and out of Mexico on June 22, 2018 in Brownsville, Texas. Immigration has once again been put in the spotlight as Democrats and Republicans spar over the detention of children and families seeking asylum at the border. Before President Donald Trump signed an executive order Wednesday that halts the practice of separating families who were seeking asylum, over 2,300 immigrant children had been separated from their parents in the zero-tolerance policy for border crossers. (Photo by Spencer Platt/Getty Images)
PHOTO: Spencer Platt/Getty Images North America/Getty Images
Now playing
02:41
Hear emotional phone calls from parents separated from their kids
mother daughter reunion
mother daughter reunion
Now playing
02:12
Watch a mother and child reunite after 55 days
BROWNSVILLE, TX - JUNE 22:  A crying  Honduran woman and her child wait along the border bridge after being denied into the Texas city of Brownsville which has become dependent on the daily crossing into and out of Mexico on June 22, 2018 in Brownsville, Texas. Immigration has once again been put in the spotlight as Democrats and Republicans spar over the detention of children and families seeking asylum at the border. Before President Donald Trump signed an executive order Wednesday that halts the practice of separating families who were seeking asylum, over 2,300 immigrant children had been separated from their parents in the  zero-tolerance policy for border crossers.  (Photo by Spencer Platt/Getty Images)
BROWNSVILLE, TX - JUNE 22: A crying Honduran woman and her child wait along the border bridge after being denied into the Texas city of Brownsville which has become dependent on the daily crossing into and out of Mexico on June 22, 2018 in Brownsville, Texas. Immigration has once again been put in the spotlight as Democrats and Republicans spar over the detention of children and families seeking asylum at the border. Before President Donald Trump signed an executive order Wednesday that halts the practice of separating families who were seeking asylum, over 2,300 immigrant children had been separated from their parents in the zero-tolerance policy for border crossers. (Photo by Spencer Platt/Getty Images)
PHOTO: Spencer Platt/Getty Images North America/Getty Images
Now playing
02:02
HHS won't give exact number of kids in custody
PHOTO: CNN
Now playing
02:13
Berman: DNA test is de facto admission of no plan
PHOTO: CNN
Now playing
02:39
Doctor describes trauma of migrant children
PHOTO: CNN
Now playing
00:52
Mother reunited with her son after 32 days
PHOTO: CNN
Now playing
01:45
Immigration attorney represented 3-year-old
(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.