"What's Canadian about Ted Cruz? His tax plan," a voice says in the 30-second ad, while an image of the Texas senator appears inside the Canadian flag's maple leaf.
The ad goes on to say that Cruz "wants a Value Added Tax" like those in Canada and "European socialist countries" before labeling Cruz as "wrong on taxes."
The ad alludes to debate over Cruz's Canadian birth and eligibility to run for president, which has been questioned by fellow GOP presidential candidate Donald Trump in recent weeks.
Cruz has argued he's eligible to run since he was born to an American mother, and Rubio himself earlier this month brushed off the citizenship debate, telling reporters, "I don't think that's an issue."
second ad from Conservative Solutions released this week argues that Cruz "calculates his positions for political gain," mentioning immigration, refugees, ethanol and trade.
Advertisements are flying in the early-voting states of Iowa and New Hampshire ahead of voting next month, with an outside group backing Cruz going after Rubio over immigration in ad last week.
The super-PAC supporting Cruz announced Tuesday it would be spending $2.5 million on advertisements in the early voting states to back the Texas senator.