House Speaker Mike Johnson (R-La.) slammed the Biden administration after a “stunning” inspector general’s report released Tuesday found nearly 300,000 migrant children have gone missing in the US.

“This administration’s failure to secure our border is facilitating what is the equivalent of a modern-day slavery operation,” Johnson told reporters on a press call Tuesday evening.

“The southern border is a national security disaster and a humanitarian catastrophe and Kamala Harris cannot be trusted to fix it,” he thundered.

“And this is one of the biggest scandals in American history; it’s one of the most tragic; and we have to hold emergency hearings.”

Immigration and Customs Enforcement (ICE) “as of May 2024” failed to locate more than 291,000 unaccompanied children that had been released to domestic sponsors, according to the Department of Homeland Security Office of Inspector General.

Another 32,000 were found and given notices to appear for immigration removal proceedings — but never showed up, the 14-page report reveals.

Just one of the eight ICE Enforcement and Removal Operations offices audited had even “attempted to locate” the missing immigrant kids — and the rate of serving them with notices to appear in immigration court at one location stood at only 16%.

A total of 448,820 unaccompanied children were shuttled from ICE to the Department of Health and Human Services (HHS) and then to sponsors nationwide between fiscal years 2019 and 2023.

HHS Secretary Xavier Becerra, amid a surge of illegal entries in 2022, pushed his staff to release the children to sponsors so quickly that he wanted the turnover to resemble an “assembly line,” according to the New York Times.

Some were put in “unsafe conditions” with sponsors, but ICE officers said the agency had “limited authority to respond” — even in cases with an unaccompanied child “whose sponsor claimed the UC was in an inappropriate relationship with her husband.”

One HHS whistleblower also revealed that an agency attorney had confessed the rapid release was due to fears of being “sued for keeping them too long,” whereas there was no threat of a lawsuit “by traffickers.” 

“Without an ability to monitor the location and status of UCs, ICE has no assurance UCs are safe from trafficking, exploitation, or forced labor,” the DHS inspector general’s report notes.

“They ended Title 42, and they made the policy choice to resettle these children with unvetted sponsors as rapidly as possible because they wanted to avoid optics about their policy,” Johnson said of the findings.

“We have no degree of certainty and no confidence at all — these innocent children who have been trafficked by cartels and all these other things — that the most unspeakable evils have not befallen them,” he added. “And that is what kept us up at night.”

The report comes after an internal DHS report earlier this month on a program flying migrants into the US found potentially massive fraud occurring among thousands of sponsors for the migrants.

The Biden administration subsequently halted the flights program to review the applicants.

President Biden crowed to delegates and attendees at the Democratic National Convention in Chicago on Monday night that immigration was under control, with crossings at their lowest level since he took office in January 2021.

“Border encounters have dropped over 50%,” Biden said in his speech. “In fact, there are fewer border crossings today than when Donald Trump left office.”

Homeland Security Committee Chairman Mark Green (R-Tenn.), who was also on the Tuesday press call, said that figure excluded more than a million admissions into the US via the CBP One app.

“It’s a shell game,” Green said. “This idea that somehow the flood of people from all over the world is diminished because of some policy from Joe Biden and Kamala Harris. It’s absolutely absurd.”

The House voted to impeach Homeland Security Secretary Alejandro Mayorkas in February for failing to enforce immigration law — but Senate Democrats voted against putting Biden’s top border official on trial.

Johnson said Biden’s remarks were part of “the largest gas lighting operation in the history of American politics.”

The Post has reached out to DHS and the Harris campaign for comment.