"I’d hate to see something like that get in his way. But a lot of people are talking about it and I know that even some states are looking at it very strongly, the fact that he was born in Canada and he has had a double passport," the real estate mogul continued.
Trump's remarks come as Cruz has seen a boost in the Iowa polls, posing a threat to Trump's dominance in the key early state. The real estate mogul has slowly started to hit Cruz on the campaign trail, recently questioning whether the Texas senator is an evangelical Christian.
Trump famously cast doubt on whether President Obama was born in the U.S., and recently dodged questions about whether he is still an Obama birther.
He has also questioned Cruz's citizenship status before. Back in 2014, Trump said that being born in Canada could hurt Cruz's chances of becoming president. But in September, Trump told ABC News that Cruz's presidential eiligibility "was checked out by every attorney and every which way and I understand Ted is in fine shape."
Cruz on Tuesday evening responded to Trump's most recent comments with a tweet about "Happy Days" character Fonzie jumping over a shark. The moment gave birth to the idiom "jumping the shark," which is used to describe when something starts to decline in popularity or quality.
— Ted Cruz (@tedcruz) January 5, 2016
On Wednesday, Cruz addressed Trump's comments directly to reporters in Iowa, calling Trump's remarks about his citizenship status "political noise," according to audio recorded by MSNBC.
"As a legal matter, the question is quite straightforward and settled law that the child of a U.S. citizen born abroad is a natural born citizen. People will continue to make political noise about it but as a legal matter it is quite straightforward," he said.