One of Donald Trump surrogate’s claimed Wednesday that the forced internment of Japanese Americans during World War II provided a “precedent” for the next administration creating a registry of Muslims living in the United States.

Carl Higbie, a former Navy SEAL and booster of the President-elect, told Fox News’ Megyn Kelly that such a registry was necessary until “we can identify the true threat” posed by Islamic extremists.

“We have in the past,” Higbie said. “We have done it based on race, we have done it based on religion, we have done it based on region.”

Kelly said that this created a “slippery slope” in which “some aggressive law enforcement actor might abuse that list.”

“There is always a case for abuse with this kind of thing,” Higbie replied, before continuing to advocate for it.

The former Navy SEAL said that though the majority of the world’s 1.6 billion Muslims are “perfectly good people,” “a small percentage” of them have aligned themselves with an extremist ideology. Higbie did not acknowledge that people of other faiths have also carried out terrorist attacks and threatened violent acts in the name of religion.

“They’re coming into our country. We need to know who they are, where they are,” he said.

Kelly pointed out that Trump said he wanted to impose a ban on immigrants from countries with a “history of terrorism,” which has been taken to mean Muslim nations. What Kansas Secretary of State Kris Kobach, an immigration hardliner who said he is advising Trump, has proposed is a national registry of immigrants and visitors from countries with active extremist organizations. Those individuals would already be living on U.S. soil, given Trump’s ban on new immigration.

“It is legal. They say it’ll hold constitutional muster,” Higbie said of the registry. “I know the ACLU is going to challenge us, but I think it’ll pass. And we’ve done it with Iran back a while ago. We did it in World War II with Japanese, which, call it what you will—”

“Come on, you’re not proposing we go back to the days of internment camps, I hope,” Kelly said.

Higbie said he was not, and Kelly admonished him, saying, “That’s the kind of stuff that gets people scared.”

“I’m just saying there is precedent for it and I’m not saying I agree with it—”

“You can’t be citing Japanese internment camps as precedent for anything the President-elect is going to do,” Kelly said, incredulously.

Higbie smiled.

“Look, the president needs to protect America first and if that means having people who are not protected under our constitution have some sort of registry so we can understand, until we can identify the true threat, and where it’s coming from, I support it,” he replied.

Some 110,000 people of Japanese ancestry were forcibly relocated and held in camps during World War II following Japan’s attack on Pearl Harbor. The U.S. government formally apologized for this stain on American history in 1988, admitting that their actions were based on “racial prejudice, war hysteria, and a failure of political leadership.”

After proposing a total ban on Muslim immigration last year, Trump said he didn’t know if he would have opposed the forced incarceration of Japanese American citizens because he wasn’t there. In March, he said he would “rule it out” but that the U.S. must be “very rigid, very vigilant.”

Watch Kelly’s interview with Higbie below.