The GOP frontrunner said supporters were simply "having a good time" doing the salute.
Donald Trump has triggered a controversy by asking supporters at rallies to swear to vote for him by raising their right hands.
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Critics say the gesture is reminiscent of Nazi rallies.
When Trump called into the Today show on Tuesday morning, he said: “Honestly, until this phone call, I didn't realize it was a problem.”
The GOP frontrunner claimed that the crowds were simply “having a good time” and they demanded that he lead them in a pledge.
“If it's offensive, if there's anything wrong with it, I wouldn't do it," he said.
He started the pledge in Orlando last week and repeated the call again in North Carolina on Monday afternoon and Monday night in Mississippi.
Donald Trump makes members of his Orlando crowd raise their right hands and swear to vote in the primary. pic.twitter.com/EVenRilJrV
— Jenna Johnson (@wpjenna) March 5, 2016
The former director of the Anti-Defamation League Abraham Foxman, who was born in Poland in 1940 and saved from the Nazis by a Catholic nanny, issued a statement to The Times of Israel, saying: “As a Jew who survived the Holocaust, to see an audience of thousands of people raising their hands in what looks like the ‘Heil Hitler’ salute is about as offensive, obnoxious and disgusting as anything I thought I would ever witness in the United States of America.”
Read: Can Donald Trump Supporters Tell His Quotes Apart from Hitler's?
The raising of the hands comes after Trump took a while to distance himself from former Ku Klux Klan leader David Duke.
At the end of February, the billionaire retweeted a Benito Mussolini quote. Mussolini, like Hitler, forced his citizens to pledge their support by raising their right hands.
"@ilduce2016: “It is better to live one day as a lion than 100 years as a sheep.” – @realDonaldTrump #MakeAmericaGreatAgain"
— Donald J. Trump (@realDonaldTrump) February 28, 2016
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