Republican presidential candidate Sen. Marco Rubio. (AP Photo/John Locher)

Sen. Marco Rubio (R-Fla.) declined to use "anchor babies" in a television interview published online Thursday, instead calling children born in the United States to parents who did not enter legally "human beings."

"When I talk about 13 million people in this country [illegally], I say 13 million human beings," Rubio said in an interview with CNBC's John Harwood published Thursday.

"Anchor babies -- people are talking about anchor babies," interjected Harwood, referring to the term Jeb Bush, Donald Trump and others have used to describe parents who may have come to the United States illegally to give birth here to children who are then automatically granted citizenship under the law. Some find the term offensive.

"Well, these are 13 million -- those are human beings. And ultimately, they are people. They are not just statistics. They are human beings with stories," responded Rubio.

Rubio, who does not agree with Trump's call to repeal the constitutional provision granting birthright citizenship, did say that the idea of "people coming to this country expressly for the purpose of having children" is a "legitimate issue" in the debate over immigration.