White House Press Secretary Sean Spicer declared unequivocally on Tuesday that Nazi leader Adolf Hitler didn't use chemical weapons during World War II, triggering a firestorm as people pointed out Nazis' use of Zyklon B pellets to kill Jews and others during the Holocaust.

"We didn't use chemical weapons in WWII. We had someone as despicable as Hitler who didn't even sink to using chemical weapons," Spicer declared as he attacked Russia for backing Syrian President Bashar al-Assad's brutal regime in Syria.

When asked about Zyklon B, Spicer clarified that he was not speaking about the Holocaust.

"He was not using the gas on his own people the same way that Assad is doing," Spicer explained.

“When it comes to Sarin gas, [Hitler] was not using the gas on his own people the same way that Assad is doing,” he said. “I understand your point. Thank you. I appreciate that. He brought them into the Holocaust centres, I understand that. I was saying in the way that Assad used them where he went into town, dropped them into the middle of town. I appreciate the clarification. That was not the intent.”