Twice in less than a year, the federal government has lost track of nearly 1,500 illegal alien children after placing them in the homes of sponsors across the country, federal officials have acknowledged, KXAN News reports.

The Health and Human Services Department (HHS) recently told Senate staffers that case managers could not find 1,488 children after they made follow-up calls to check on their safety from April through June– or roughly 13 percent of all unaccompanied children the administration moved out of shelters and foster homes during that time.

The agency first disclosed that it had lost track of 1,475 children late last year, the Associated Press reports, when agency staff were questioned at a Senate hearing in April. Lawmakers asked HHS officials since then how they had improved the agency’s child protection policies since the Senate was first made aware of the problem.

“The fact that HHS, which placed these unaccompanied minors with sponsors, doesn’t know the whereabouts of nearly 1,500 of them is very troubling,” Republican Sen. Rob Portman of Ohio, the panel’s chair, said. “Many of these kids are vulnerable to trafficking and abuse, and to not take responsibility for their safety is unacceptable.”

HHS spokeswoman Caitlin Oakley disputed the notion that the children were “lost.” She said in a statement, “Their sponsors, who are usually parents or family members and in all cases have been vetted for criminality and ability to provide for them, simply did not respond or could not be reached when this voluntary call was made.”

The Associated Press reports that since October 2014, the federal government placed more than 150,000 unaccompanied minors with parents or other adult sponsors who were expected to care for the children. The children were to attend school and receive aid to seek legal status in immigration court.

This past week, members of a Senate subcommittee introduced bipartisan legislation aimed at requiring the agency to take responsibility for the care of migrant children, even when they are no longer in its custody.

An Associated Press investigation found in 2016 that more than two dozen unaccompanied children had been sent to homes where they were sexually assaulted, starved or forced to work for little or no pay. At the time, many adult sponsors didn’t undergo thorough background checks, government officials rarely visited homes and in some cases had no idea that sponsors had taken in several unrelated children.

According to the Senate Permanent Subcommittee on Investigations, the HHS last year offered post-placement services to about one-third of unaccompanied minors. The problem is that many of these children “disappear” before social workers can follow up with them and they never show up in court.

From April to June, HHS called 11,254 children the agency had placed with sponsors. It discovered that 25 of the children ran away and 1,488 could not be located.

The legislation is aimed to ensure that HHS improves its background check system before placing children with sponsors, and is required to notify state governments before sending children to their respective states.

“The already challenging reality migrant children face is being made even more difficult and, too often, more dangerous,” said Sen. Tom Carper of Delaware. “This simply doesn’t have to be the case and, as this legislation demonstrates, the solutions don’t have to be partisan.”

Here’s a question for the senators: why aren’t these children being repatriated to their home countries and re-united with their families in Guatemala, El Salvadore, Mexico, or anywhere else? Why are taxpayers paying for sponsors and education for children who are brought to the U.S. illegally?

The priority shouldn’t be background checks and screening– but deportation to ensure they are placed in their homes of origin.