Donald Trump has repeatedly called for all immigrants from mostly-Muslim countries to undergo "extreme vetting".
Carl Higbie, spokesman for a major pro-Trump super PAC, said a 'Muslim registry' would be constitutionally sound.
Mr Higbie, a former Navy SEAL, told Fox: "It is legal, they say it will hold constitutional muster. I know the the ACLU is going to challenge it, but I think it will pass
"And we’ve done it with Iran back - back a while ago, we did it during World War II with Japanese, which, call it what you will it may be wrong."
The host, Megyn Kelly, quickly questioned his comment, stating: "Come on, you’re not proposing we go back to the days of internment camps.
"You know better than to suggest that, that’s the kind of thing that gets people scared, Carl."
Mr Higbie, a regular guest on Fox News, asserted he was not proposing internment camps but simply saying they are a legal precedent for a registry.
Clarifying his position, he said: "Look, the president needs to protect America first, and if that means having people that are not protected under our Constitution have some sort tor registry so we can understand - until we can identify the true threat and where it’s coming from, I support it."
A member of Donald Trumps's transition team, Kris Kobach has said the President-elect is considering implementing such a measure using an executive order while avoiding the need of getting Congressional approval.
Mr Higbie is a spokesman for the pro-Trump super PAC (political action committee) - Great America PAC.
A super PAC is an organisation that can raise unlimited funds for political purposes as long as they do not donate directly to candidate campaigns or parties.
Great America raised millions to help Mr Trump's bid for the presidency.
From 1942 to 1946, around 120,000 US residents and citizens of Japanese ancestry were interned against their will in camps across the United States.
In 1988, President Ronald Reagan signed a bill offering $20,000 of reparation to each surviving internee.
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