AP Photo/Mary Altaffer
"It's time for Ted Cruz to either settle his problem with the FACT that he was born in Canada and was a citizen of Canada, or get out of race," Trump wrote on Twitter.
Cruz was born in Canada to an American mother. Most legal experts believe that Cruz meets the Constitutional requirement that presidents are "natural-born" citizens.
But Trump has argued on a daily basis that voters should not back Cruz if there's any doubt over his eligibility for the Oval Office.
It's just one of several lines of attack that Trump has deployed against Cruz as they enter the final stretch as the top two candidates in the February 1 Iowa caucus. Trump frequently cites the fact that some top legal scholars have noted that the courts have yet to officially define "natural-born" citizenship.
"As you noticed, a number of very top constitutional lawyers have come and said - he was born in Canada. He didn't tell people. He said he didn't know about it. Until 15 months ago, he was a Canadian citizen. He was joint with the United States, but he was a Canadian citizen until 15 months ago," Trump said Sunday on CBS' "Face the Nation," according to the show's transcript.
"He was a United States senator, I guess nobody figured this out, and he was citizen of Canada," he continued. "And there are lot of people now that are saying he was born in Canada- he was born on Canada's soil, on Canadian soil- and he cannot run."
Trump has even suggested that Cruz could run for prime minister in Canada instead of president of the US:
Cruz did not renounce his Canadian citizenship as a US Senator- only when he started to run for #POTUS. He could be Canadian Prime Minister.
- Donald J. Trump (@realDonaldTrump) January 23, 2016