President Biden’s border security czar has been given an ultimatum: Resign or be fired.

Chris Magnus, the head of US Customs and Border Protection, is being forced out of his job as the number of illegal border crossings surged to record highs in fiscal year 2022, sources told the Associated Press on Friday.

Magnus, 61, said in a statement to the Los Angeles Times, which was first to report the ultimatum, that he would not step down after being asked Wednesday by Homeland Security Secretary Alejandro Mayorkas to consider his position.

“I am excited about the progress I made and look forward to continuing that work,” Magnus said.

Despite the supposed “progress,” a record 2.4 million migrants were stopped at the US border with Mexico in the fiscal year that ended Sept. 30 — a 37% surge from a year earlier.

Mayorkas’ reported demand comes just weeks after Politico reported that Magnus was missing from or sleeping through key meetings on the ongoing migration surge.

“He’s not in the game,” an administration official told the outlet at the time.

“Every time there’s a meeting and he’s in it, we’ll get to a conclusion and Magnus will have some sidebar issue that he wants to raise and we’re all like, ‘What the f–k is that about?’”

In the same report, Magnus was accused of ripping other agencies to co-workers and superiors, failing to secure alliances needed to address the surge of illegal border crossings, and being more concerned with claims of racism and violence against rank-and-file agents than stopping the flow of migrants.

Brandon Judd, president of the National Border Patrol Council, said he welcomed Magnus’ departure.

“I think it’s a good thing,” Judd said. “He was just working on policies that were just going to incentivize more criminal activity. The vehicle pursuit policy, had he implemented that, all it would have done is increase criminal activity.”

Magnus, a former police chief in Tucson, Ariz., Fargo, ND, and Richmond, Calif., had announced in May that he was revisiting guidelines for agents to pursue vehicles following a number of fatal collisions.

He was also behind the investigation that found Border Patrol agents on horseback used “unnecessary” force against a group of Haitian migrants in Del Rio, Texas, in September last year — despite there being no evidence that any migrants were whipped with reins.

Magnus’ ultimatum is part of a larger shakeup expected at the Department of Homeland Security as officials grapple with Biden’s ongoing border crisis, which has seen officials struggle to cope with the influx of migrants flooding into the US.

It also comes as Republicans inch closer to taking control of the House in January and are expected to launch probes into the border saga — with impeachment of Mayorkas being publicly discussed.

With Post wires