(WASHINGTON) — More than 2,400 children were waiting to get picked up from Border Patrol stations along the U.S.-Mexico border as of Friday, officials said, and the federal agencies in charge of caring for them can’t agree on why most of them aren’t being quickly moved into children’s shelters.The minors, referred to in government circles as “unaccompanied alien children,” or UACs, are typically older children and teens who are traveling without their parents, although toddlers and infants also turn up in groups of traveling migrants.Under U.S. law, the minors are supposed to spend less than 72 hours in Border Patrol custody before being transported to one of dozens of children’s shelters scattered across the country and run by the Department of Health and Human Services. Transportation is the job of U.S. Immigration and Customs Enforcement.U.S. officials agree the detention facilities – oftentimes cement blocks without beds – are no place for children and that it’s imperative to move younger migrants out within 72 hours of being apprehended.But as the number of unaccompanied migrant kids soared to 9,000 in the month of April alone – a final tally for May is expected to be even higher – the U.S. government has left many kids waiting at detention facilities for several days at a time.Earlier this month, a 16-year-old boy died at a detention facility in Texas after spending a week in Border Patrol custody and experiencing flu-like symptoms.When asked why hundreds of thousands of kids are stuck in border facilities on any given day, the Homeland Security Department – which oversees border operations and ICE – points to Health and Human Services.Acting Secretary Kevin McAleenan told reporters on a press call late Thursday that the kids were waiting because HHS was “out of bed space” and noted that Congress hasn’t approved a $2.8 billion request for emergency spending to care for migrant children.But HHS says that isn’t the case. While the agency says it needs the emergency money approved by Congress this June so it can continue to pay the privately run children’s shelters, the agency has insisted repeatedly to ABC News that it is not out of bed space and will accept any child transported into its custody so long as the child is medically cleared.Mark Weber, a spokesman for HHS, said late Thursday in response to McAleenan’s comments that the agency’s “shelters have beds available and they are ready to receive UAC when processed by DHS.”Weber said the agency remains in “daily contact” with DHS on the number of children being referred to its care.HHS was forced to shut down one of its biggest children’s shelters in Texas, called Tornillo. But the agency has said it has the ability to ramp up capacity at one of its largest shelters, Homestead in Florida, and that it is looking at opening up new shelter sites in places like Fort Sill in Oklahoma.One possible issue could be the time lag between a child’s apprehension by border authorities and when HHS notifies DHS that it can accept placement of a child. That official acceptance by HHS is what triggers ICE to transport the child to one of its shelters. An ICE spokesman referred questions to DHS and HHS but said it’s planning on transporting about 45,000 kids per year based on current levels. Copyright © 2019, ABC Radio. All rights reserved.