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White House Press Secretary Sean Spicer apologized Tuesday evening after causing a firestorm for saying that Adolf Hitler "didn't even sink to using chemical weapons" against his own people like Syrian strongman Bashar Al-Assad.

Spicer, speaking from the White House podium at the daily press briefing, said that Hitler, whom he called "despicable," did not use "the gas on his own people the same way Assad used them."

He sought to clarify his remarks in three separate follow-up statements — which did little to help — and then provided a full-blown apology.

"To draw any kind of comparison to the Holocaust was inappropriate and insensitive," he told NBC News.

He later continued, referring to the Jewish holiday of Passover, "I’m absolutely sorry, especially during a week like this to make a comparison that is inappropriate and inexcusable."

But that was well after the outrage on social media was already in motion, with reporters and public figures blasting Spicer's comments — and saying they were particularly offensive coming during Passover.

I hope @PressSec takes time to visit @HolocaustMuseum. It's a few blocks away. https://t.co/24fNoMUyS8 — Chelsea Clinton (@ChelseaClinton) April 11, 2017

Yeah. Jews weren't really Germans and Hitler's gassings weren't "dropped down" like Assad's serin attacks. Got it. https://t.co/GClZxKUfsa — Eli Stokols (@EliStokols) April 11, 2017

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Having visited Auschwitz last summer, and seen the remains of the gas chambers, I find this an astonishing comment. https://t.co/pyvjjbxQv2 https://t.co/AOflaPuQmp — Glenn Kessler (@GlennKesslerWP) April 11, 2017

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Overnight, Israel's Transportation Minister Yisrael Katz called Spicer's comments "grave and outrageous."

"There is a moral obligation that precedes policy. We must demand that he apologize or resign," he said in a statement on Twitter.

On Wednesday, Katz told Israel Army Radio that Spicer's apology had been acceptable, and "it was good that [it] was very clear."

On Tuesday, the Anne Frank Center for Mutual Respect called on President Donald Trump to can Spicer.

"Sean Spicer now lacks the integrity to serve as White House press secretary, and President Trump must fire him at once," Steven Goldstein, the organization's executive director, said in a statement.

House Minority Leader Nancy Pelosi echoed those sentiments.

“While Jewish families across America celebrate Passover, the chief spokesman of this White House is downplaying the horror of the Holocaust," she wrote in a statement. "Sean Spicer must be fired, and the President must immediately disavow his spokesman’s statements. Either he is speaking for the President, or the President should have known better than to hire him.”

When asked by NBC News if his job is safe, Spicer reiterated his apology.

"Well, you know what, I made a mistake. I’m owning up to it," he said. "And you know, this is, obviously I expect, I’d hope, that everyone understands that we all make mistakes and ask for forgiveness."

The U.S. Holocaust Memorial Museum used Spicer's gaffe as a moment to remind of the horrors of the Holocaust.

At the briefing, Spicer pointed out that Assad dropped chemical weapons in the "middle of towns."

U.S. officials said the Assad regime used Sarin in strikes on the Syrian people in a deadly attack last week that prompted U.S. military strikes in retaliation.

Nazis murdered Jews in gas chambers during the Holocaust by the millions with the use of chemical gas agents like Zyklon B.

Spicer acknowledged that Hitler did bring gas "into the Holocaust centers ... I understand that."

Before his apology, Spicer had sought to clarify his remarks in multiple statements and said he was not trying to diminish the Holocaust.

"In no way was I trying to lessen the horrendous nature of the Holocaust," Spicer said in his third attempt at clarification. "I was trying to draw a distinction of the tactic of using airplanes to drop chemical weapons on population centers. Any attack on innocent people is reprehensible and inexcusable."