Yad Vashem, the Holocaust Museum and Remembrance Center in Jerusalem has invited White House spokesman Sean Spicer to visit the center’s website and learn about the Nazi extermination camps after he made controversial remarks on Hitler at a press briefing.

Spicer said during his daily press briefing as he was discussing the recent chemical weapons attack in Syria that killed 87 people and that US President Donald Trump blamed on the Syrian regime of President Bashar Assad: "You had someone as despicable as Hitler who didn't even think of using chemical weapons.''

When a reporter asked Spicer if he wanted to clarify his comments, he said: "I think when you come to sarin gas, there was no, he was not using the gas on his own people the same way that Assad is doing."

He later apologized and said he should not have made that comparison.

"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," he told CNN’s Wolf Blitzer.

"I mistakenly used an inappropriate, insensitive reference to the Holocaust. I apologize. It was a mistake to do that. I shouldn't have done it and I won't do it again."