Donald Trump’s campaign on Wednesday denied a report that said the Republican presidential nominee had repeatedly asked an international foreign policy expert why the U.S. couldn’t use nuclear weapons.

MSNBC’s Joe Scarborough claimed that the expert, who he did not name, advised the real estate mogul earlier this year during an hour-long briefing in which Trump had allegedly asked about using nuclear weapons three times, Scarborough said on Morning Joe.

Trump’s campaign spokeswoman Hope Hicks said in a statement to TIME that there was “no truth” to the report.

Trump has spoken publicly about his thoughts on nuclear weapons in other interviews, saying they should be the “absolute last step” and calling proliferation a serious problem, while also noting he would “never, ever” rule out using them and suggesting that some other countries might need to a develop nuclear arsenal.

Here’s what Trump has said during the five times he has talked about nuclear weapons during the campaign so far:

“Biggest problem, to me, in the world, is nuclear, and proliferation”

Trump said nuclear capability was the “single biggest problem” facing the world in a wide-ranging interview with the New York Times in March. Asked whether the U.S. should be the first to launch a nuke during a confrontation with an enemy, Trump said that should be the “absolute last step.” “Power of weaponry today is beyond anything ever thought of, or even, you know, it’s unthinkable, the power,” he said. “It’s a very scary nuclear world,” he added. “Biggest problem, to me, in the world, is nuclear, and proliferation.”

“I don’t want to rule out anything”

Trump reiterated the fact that he would be the “last to use nuclear weapons” during an April interview with NBC’s Today show. But he said the option is still on the table. “I don’t want to rule out anything,” he said. “I will be the last to use nuclear weapons. It’s a horror to use nuclear weapons.” “I will not be a happy trigger like some people might be,” he added. “But I will never, ever rule it out.”

“We have nuclear arsenals which are in very terrible shape”

In the same New York Times interview in March, Trump indicated that Japan and South Korea might need to obtain their own nuclear arsenal to protect themselves from North Korea and China if the U.S. is unable to defend them. “It’s a position that we have to talk about,” he said. “If the United States keeps on its path, its current path of weakness, they’re going to want to have that anyway with or without me discussing it, because I don’t think they feel very secure in what’s going on with our country.”

“At some point, we cannot be the policeman of the world. And unfortunately, we have a nuclear world now,” he later added.

Trump also said Japan and Korea might need to pay more for their own defense. “You know, when we did these deals, we were a rich country. We’re not a rich country. We were a rich country with a very strong military and tremendous capability in so many ways. We’re not anymore,” he told the newspaper. “We have a military that’s severely depleted. We have nuclear arsenals which are in very terrible shape. They don’t even know if they work.”

“Maybe it’s going to have to be time to change”

Trump discussed his stance further with CNN in late March, saying the U.S. might need to change its decades-old policy of preventing Japan from getting a nuclear weapon. “Can I be honest are you? Maybe it’s going to have to be time to change, because so many people, you have Pakistan has it, you have China has it. You have so many other countries are now having it,” Trump told CNN’s Anderson Cooper. Trump later appeared to contradict himself, saying he doesn’t “want more nuclear weapons.”

“I will have a military that’s so strong and powerful, and so respected, we’re not gonna have to nuke anybody”

Trump “wouldn’t be nuking anybody” because he wouldn’t need to, given America’s defense force, he said in an interview with GQ magazine last November. “I will have a military that’s so strong and powerful, and so respected, we’re not gonna have to nuke anybody,” he said, adding that he would be “amazingly calm under pressure.” Still, Trump told the magazine he wouldn’t get rid of the nuclear weapons because “other people have them” and are “unfortunately gaining more and more.” “It is highly, highly, highly, highly unlikely that I would ever be using them,” he added.

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