WASHINGTON — White House press secretary Sean Spicer called Republican mega-donor Sheldon Adelson Tuesday to personally apologize after sparking a controversy by claiming Adolf Hitler never used chemical weapons, in what was criticized as a downplaying of the Holocaust.

“Sean called shortly after and said he made a terrible mistake and apologized if he was offensive,” Adelson’s spokesman Andy Aboud said in a statement, according to Politico’s Alex Isenstadt.

Spicer himself later confirmed to CNN that he spoke with Adelson.

It was not immediately clear how the call was prompted, or how much contact Adelson normally has with the Trump administration.

Adelson, a billionaire Jewish casino magnate whose deep pockets have made him a kingmaker in the GOP, donated tens of millions to Trump’s election campaign and to his inauguration ceremony.

He and his wife were on the dais for Trump’s inaugural oath-taking, a rare honor for campaign funders.

Adelson, who also donates heavily to pro-Israel causes and owns the free Israeli daily Israel Hayom, is seen as close to Prime Minister Benjamin Netanyahu.

On Wednesday morning, his tabloid noted anger at Spicer on its front page, and a report on the brouhaha called the comments “muddled.”

The phone call came after Spicer took to CNN to publicly apologize for remarks he made hours earlier that stunned the Washington press corps, members of Congress, Jewish groups and Holocaust scholars.

“We didn’t use chemical weapons in World War II,” Spicer told reporters during a White House press briefing. “You know, you had someone as despicable as Hitler who didn’t even sink to using chemical weapons.”

Prompted to explain his initial comments, Spicer then issued a number of clarifications, saying he knew millions of Jews and other victims of the Nazis were killed in “Holocaust centers” in Nazi-occupied Europe, many in gas chambers, but that “when it comes to sarin gas, [Hitler] was not using the gas on his people the same way that Ashad [sic] is doing.”

Speaking with CNN’s Wolf Blitzer later in the day, Spicer expressed remorse for the comparison and tried to distance his comments from his boss, US President Donald Trump.

White House Spokesman Sean Spicer speaks during the daily press briefing at the White House in Washington, DC, April 3, 2017. (AFP/Nicholas Kamm)

White House Spokesman Sean Spicer speaks during the daily press briefing at the White House in Washington, DC, April 3, 2017. (AFP/Nicholas Kamm)

“I was obviously trying to make a point about the heinous acts that Assad had made against his own people last week, using chemical weapons and gas, and frankly I mistakenly used an inappropriate, insensitive reference to the Holocaust,” he said. “For that, I apologize. It was a mistake to do that.”

“My comments today did not reflect the president’s, were a distraction from him and frankly were misstated, insensitive and wrong,” he added. “Obviously it was my blunder.”

Despite Spicer’s repeated attempts to smooth over his impromptu remarks, House Minority Leader Nancy Pelosi called on Trump to fire him over the incident.

“While Jewish families across America celebrate Passover, the chief spokesman for this White House is downplaying the horrors of he Holocaust,” Pelosi said in a statement, adding that Spicer “must be fired” and Trump must “disavow” his statements.

“Either he is speaking for the President, or the President should have known better than to hire him,” she said.