In recent days, multiple news outlets have reported the federal government lost track of nearly 1,500 immigrant children placed with sponsors, based on congressional testimony last month from a top Health and Human Services official, eliciting concern.

"The U.S. lost track of 1,475 immigrant children last year. Here's why people are outraged now," the Washington Post headline read this week. "Some 1,500 immigrant children unaccounted for, federal official says," Fox News reported in its own recent headline. The New York Times' Ron Nixon reported the story first, on April 26, with the headline, "Federal agencies lost track of nearly 1,500 migrant children placed with sponsors."

Those stories and others were based on remarks made by Health and Human Services Acting Assistant Secretary Steven Wagner in a Senate hearing on April 26 before a Senate Homeland Security subcommittee. Wagner testified that the Office of Refugee Resettlement, the HHS office responsible for unaccompanied immigrant minors or UACs, as the government calls them, "was unable to determine with certainty the whereabouts of 1,475" immigrant children the federal government had placed with sponsors. "Unaccompanied alien children," or UACs, as the government officially describes them, are often placed with family members already living in the U.S.

Get Breaking News Delivered to Your Inbox

"From October to December 2017, ORR attempted to reach 7,635 UAC and their sponsors," Wagner said in his written testimony last month. "Of this number, ORR reached and received agreement to participate in the safety of well-being call from approximately 86 percent of sponsors. From these calls, ORR learned that 6,075 UAC remained with their sponsors. Twenty-eight UAC had run away, five had been removed from the United States, and 52 had relocated to live with a non-sponsor. ORR was unable to determine with certainty the whereabouts of 1,475 UAC."

Wagner also clarified in his testimony that it is "HHS' long-standing interpretation of the law that ORR is not legally responsible for children after they are released from ORR care." But HHS is "exploring the question of ORR"s responsibilities in relation to children who are released to sponsors, and whether the level of responsibility would differ depending on the child's relationship to his or her sponsor."

So, did the federal government lose track of nearly 1,500 unaccompanied immigrant minors?

The children might not necessarily be lost, HHS Deputy Secretary Eric Hargan said in a lengthy statement Tuesday calling claims that the children are "lost," "completely false." ORR just has simply been unable to reach the sponsors in a follow-up call 30 days after placing the children with the sponsor, he said. Hargan said some of the sponsors may not be picking up the phone because they are not in the country legally.

"These children are not 'lost;' 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," Hargan's statement said. "While there are many possible reasons for this, in many cases sponsors cannot be reached because they themselves are illegal aliens and do not want to be reached by federal authorities. This is the core of this issue: In many cases, HHS has been put in the position of placing illegal aliens with the individuals who helped arrange for them to enter the country illegally. This makes the immediate crisis worse and creates a perverse incentive for further violation of federal immigration law."

Whatever the reason for being unable to reach these sponsors, the federal government acknowledges it cannot verify the location of these immigrant minors.

But that was far from the only controversy about immigrant children this week. Some liberal activists incorrectly tweeted photos of young-looking immigrants at the U.S.-Mexico border in steel cages and blamed the current administration's policy of separating children from their parents. Mr. Trump seized on that error.

The photos were taken by The Associated Press in 2014, when President Barack Obama was in office. The photo captions reference children who crossed the border as unaccompanied minors.

Early Tuesday, Trump tweeted: "Democrats mistakenly tweet 2014 pictures from Obama's term showing children from the Border in steel cages. They thought it was recent pictures in order to make us look bad, but backfires. Dems must agree to Wall and new Border Protection for good of country...Bipartisan Bill!"

The immigration debate has reached a fever pitch in recent months following reports that since October about 700 children crossing the U.S.-Mexico border have been separated from their parents.