The former president, speaking at a campaign event in North Carolina, referred to a question posed to Democratic President Joe Biden this week about the possibility of Israel targeting Iran's nuclear program.

"They asked him, what do you think about Iran, would you hit Iran? And he goes, 'As long as they don't hit the nuclear stuff.' That's the thing you want to hit, right?" Trump told a town hall style event in Fayetteville, near a major US military base.

Biden was asked on Wednesday whether he would support strikes against Iranian nuclear sites and the US president told reporters: "The answer is no."

"I think he's got that one wrong," Trump said Friday, in response to a participant's question about the issue. "Isn't that what you're supposed to hit? I mean, it's the biggest risk we have, nuclear weapons," he said.

"When they asked him that question, the answer should have been, hit the nuclear first, and worry about the rest later," Trump added.

"If they're going to do it, they're going to do it. But we'll find out whatever their plans are."

Biden on Wednesday expressed his opposition to such strikes against Iran's nuclear facilities, in response to the firing of nearly 200 Iranian missiles towards Israel.

"We'll be discussing with the Israelis what they're going to do," he said, adding that all G7 members agree Israel has "a right to respond, but they should respond in proportion."

Trump, locked in a tooth-and-nail presidential election battle with US Vice President Kamala Harris, the Democratic nominee, has spoken little about the recent escalation in tensions in the Middle East.

He issued a scathing statement this week, holding Biden and Harris responsible for the crisis.