The press secretary has made headlines in the past for exaggerating the size of President Donald Trump’s inauguration crowd, searching through staffers’ phones in a crackdown on leaks, and citing a Fox News personality to say British officials spied on Trump’s team.

But it appeared to be the first time he apologized. In fact, it seemed to be the first significant apology from Trump’s White House, which has weathered controversies, inappropriate comments and investigations with an apparent axiom: Better to be strong and wrong than to say sorry.

Spicer told POLITICO on Tuesday night that it was his decision to issue the public apology and that he would be back at the White House podium this week.

“I made a mistake by trying to make a comparison that was completely wrong,” he said. “I don’t even know how to explain it. It was a straight up mistake.”

Spicer did not seem to be at risk of losing his job, two White House officials and two advisers said, even though the president was displeased with his comments. “If the administration can regain the message, I think Sean will be OK. If not, I think he could be in trouble,” one outside adviser said. A White House official said Trump hadn’t shown anger toward Spicer, even though he had after previous briefings.

The television appearance was the strongest of several attempts to move past Tuesday’s press briefing, when Spicer sought to criticize the Russian government for its support of dictator Bashar Assad by comparing last week’s chemical attack on civilians in Syria to the actions of Adolf Hitler.

“We didn’t use chemical weapons in World War II,” Spicer told reporters. “Someone who is despicable as Hitler who didn’t even sink to using chemical weapons.”

In fact, Hitler’s Nazi Germany did use chemical weapons. Many of the Jews who died in the Holocaust were killed in gas chambers using Zyklon B and other poisons. And sarin gas, the weapon believed to have been used by Assad’s regime, was first created and weaponized by Nazi scientists in 1938.

Spicer’s allies say he has almost an impossible job: Defending a boss who often contradicts himself, makes statements that prove to be untrue and believes he is his own best spokesman. But while Spicer’s briefings sometimes become comically combative, Trump appreciates a vigorous defense, allies and advisers say.

“Until you’ve stood at that podium, you have no idea how hard it is day in and day out to never make a mistake,” said Ari Fleischer, a press secretary for George W. Bush. “Sean made a big one today. He handled it properly. He apologized. Now, he’s going to take a pounding, and he’s going to move forward.”

Fleischer said he had to issue formal apologies twice, for incorrectly blaming violence in the Middle East on Bill Clinton and for urging Iraqis to shoot Saddam Hussein. Both times, Fleischer said, he marched into the Oval Office and apologized, and Bush was “ticked” but soon forgiving. Fleischer said people shouldn’t assume the worst of Spicer and should save their anger for “actual Holocaust deniers.”

Apologizing does not come naturally to Spicer’s boss. Trump did it only once during his 2016 campaign, after a tape surfaced of him saying he grabbed women by the genitals without asking permission. But he didn’t seem to really want to, and advisers said it took significant negotiations.

“This was locker room talk, a private conversation that took place many years ago,” Trump said in his apology. “Bill Clinton has said far worse to me on the golf course -- not even close. I apologize if anyone was offended.”

During the briefing Tuesday, Spicer tried to fix his initial mistake. But he only dug in deeper, saying that Hitler “was not using the gas on his own people in the same way that Assad is doing.” (Hitler’s systematic murder of Jews — including many in Germany — and of people from other groups left millions dead.)

Spicer told POLITICO that by the time he got to his office after the briefing, he knew he had messed up. One person who spoke to him Tuesday said he hoped a written clarification would calm the tempest. The White House issued a statement saying Spicer did not intend to “lessen the horrendous nature of the Holocaust,” but it did not quell the flood of criticism.

MSNBC fact-checked Spicer with a chyron summarizing what the press secretary had said and adding parenthetically that “Hitler gassed millions.” The Anne Frank Center accused Spicer of engaging in Holocaust denial. House Minority Leader Nancy Pelosi called for the White House to fire him. Even Alex Jones, the conspiracy theorist and Trump supporter, criticized Spicer.

Spicer called the office of Republican mega-donor Sheldon Adelson, a major giver to Jewish causes, soon after making the statements, according to Andy Abboud, an Adelson spokesman. “Sean called shortly after and said he made a terrible mistake and apologized if he was offensive,” Abboud said.

The White House had earlier faced criticism from Jewish groups for not mentioning Jews in an annual Holocaust statement, but Adelson has generally had a friendly relationship with Trump and likes his hawkish support of Israel.

Spicer struck a contrite tone in the unannounced appearance on CNN, even as Blitzer ribbed him for mispronouncing Assad’s name and asked whether he had a credibility problem.

“When you make a mistake, you own it,” Spicer said. Blitzer later praised Spicer for owning up to his error.

But Spicer made another verbal gaffe on the program, saying he was sorry his comments were a distraction from Trump’s “attempts to destabilize the region.”

The United States actually hopes to stabilize the Middle East.

Louis Nelson, Madeline Conway and Alex Isenstadt contributed to this report.