FORT WORTH, Texas – The federal foster care system was unprepared to house the record nearly 19,000 unaccompanied children who came to the United States in March, so the Biden administration asked some states to temporarily house them.

GOP governors in Iowa, Nebraska, South Carolina, South Dakota and Wyoming said no. The governors claim that unaccompanied children would displace those already in state foster care or limit states' ability to make new placements.

"Nebraska is declining their request because we are reserving our resources for serving our kids," Nebraska Gov. Pete Ricketts said in an April 13 news release. "I do not want our kids harmed as the result of President Biden's bad policies."

But federal officials note that care providers for unaccompanied children are paid via federal grants and operate separately from state child welfare systems.

Caring for unaccompanied children does require some limited state resources, because states license and monitor foster care providers contracted by the Office of Refugee Resettlement, the federal agency in charge of housing unaccompanied minors.

However, there currently are no federally funded foster care providers for unaccompanied minors in any of the five states where GOP governors have expressed concerns, U.S. Department of Health and Human Services records show.

The children who have been placed there are most likely being taken in by family members, according to Mary Miller Flowers, senior policy analyst for child protection at the Young Center for Immigrant Children's Rights, an advocacy group in Chicago.

The issue of unaccompanied minors will continue to roil states as immigration remains one of the most potent political issues for many Republican governors. Some states, such as Texas, are pushing to end the Biden administration's policy allowing migrants, including unaccompanied children, into the country while they await hearings.

"The heartbreaking humanitarian crisis on our border was created by the Biden Administration," tweeted South Carolina Gov. Henry McMaster shortly after issuing an executive order on April 12 directing state-licensed foster care facilities to reject the placement of migrant children.

But the Trump administration reduced the number of beds for unaccompanied children and closed government requests for bids to provide shelter and services, according to government grants and U.S. Department of Health and Human Services bed capacity data.

Law enforcement encountered 18,663 unaccompanied children at the U.S.-Mexico border in March, the highest number of any month on record for this group of migrants, according to U.S. Customs and Border Protection data analyzed by the Migration Policy Institute, a nonpartisan think tank.

After apprehension, unaccompanied children are by law supposed to spend no more than 72 hours in Customs and Border Protection (CBP) custody before being transferred to the care of the Office of Refugee Resettlement. This transfer is particularly important because CBP facilities are ill-equipped to hold children, especially for long periods of time, according to Flowers.

To deal with the surge, HHS has opened about a dozen emergency intake sites and influx care facilities in California, Texas, Michigan and Pennsylvania. These sites, located inside convention centers, fairgrounds and military bases, do not have to be licensed by the state and are meant to hold unaccompanied children only for a short period of time while they are tested for COVID-19, quarantined and placed with a vetted family member or sponsor.

In more than 80% of cases, the child has a family member in the U.S., according to HHS. Finding long-term foster care for those who don't have a sponsor falls on the Office of Refugee Resettlement and its network of more than 200 providers in 22 states.

Foster care providers who care for unaccompanied children include the United States Conference of Catholic ­Bishops, Lutheran Immigration and Refugee Service, BCFS Health and Human Services, Upbring, and Urban Strategies.

While the number of unaccompanied child-migrant arrivals fell during the early months of the pandemic, the arrivals began to grow in August and accelerated after a court ordered the Trump administration in November to exempt unaccompanied children from the Title 42 expulsion order. That order authorizes the CDC director to suspend the introduction of people into the U.S. to protect public health.

Predictably, the number of unaccompanied minors crossing the border subsequently rose, but the Trump administration did not build the capacity to accommodate them, Office of Refugee Resettlement bed capacity data show.

"This is not our problem," said Iowa Republican Gov. Kim Reynolds on the "Need to Know with Jeff Angelo" program on April 8. "This is the president's problem. He's the one that has opened the border and he needs to be responsible for this, and he needs to stop it."