As a California court deadline came and went Tuesday for the Trump administration to reunite 102 undocumented immigrant children under the age of 5 with their parents, Sen. James Lankford came to the administration’s defense after it did not fully meet the court’s demands.

Dozens of the children are still at temporary housing facilities as the Justice and Health and Human Services Departments vet those who have claimed to be the children’s parents through DNA tests, criminal background checks, and other means.

Some people who have claimed parentage have been human traffickers, Lankford told MSNBC on Tuesday.

“The challenge is some of those individuals are not their parents,” Lankford said. “Some of those individuals were traffickers claiming to be their parents. So they’re doing DNA tests to be able to evaluate, ‘Are these really relatives?’”

Children who are not claimed by any verifiable parents or relatives will be placed in foster care.

“If they’re not a relative, then we’re not going to go back and place them with someone who is not a relative,” Lankford said. “We’ve got to be able to figure out what to do with them.”

There’s another complication frustrating the feds’ efforts to reunite families, Lankford said: Some parents aren’t ready to take back their children.

“Some of the adults are saying ‘We don’t want to take these children. We want to be deported, and we’ll start all over again and come back. This time it will be easier to not have to travel a month … through Mexico with a child. We’ll just try to catch up with them later,’” Lankford said.

A June 26 court order in California gave the administration two weeks to reunite children under the age of five with their parents, a deadline Justice and HHS officials said could not be met almost from the moment it was issued. The feds were given a month to reunite all other children with their families.

Officials have said it they plan to reunite 75 of the 102 children under 5 with their parents, according to a court filing from DOJ lawyers Tuesday. Twenty-two others had parents who either were in the custody of other criminal agencies; were being treated for disease; were living with someone with a criminal background; had a criminal background themselves; or had a credible claim of child abuse against them. Five children had people claiming parentage who were not actually their parents.

There are at least 2,900 other minors between 5 and 18 years old who are still waiting to be reunited with their relatives.