Donald Trump: Babies Born To Undocumented Immigrants Aren't U.S. Citizens

"We have to start a process where we take back our country. Our country is going to hell."

WASHINGTON -- Not only does Donald Trump support ending birthright citizenship, the real estate mogul now says children born to undocumented immigrants on U.S. soil aren't American citizens at all.

"I don't think they have American citizenship and if you speak to some very, very good lawyers -- and I know some will disagree -- but many of them agree with me and you're going to find they do not have American citizenship. We have to start a process where we take back our country. Our country is going to hell," Trump said in an interview with CNN on Tuesday night.

The current frontrunner for the Republican presidential nomination added that he wants to "test out" his views in court and that he would ultimately allow "good ones" to apply to return to the U.S. once all undocumented immigrants were deported.

"What happens is they're in Mexico, they're going to have a baby, they move over here for a couple of days, they have the baby -- [the lawyers are] saying it's not going to hold up in court," he said.

There were an estimated 4.5 million U.S.-born children younger than the age of 18 living with at least one undocumented parent in 2012, according to a 2014 Pew Hispanic Center report. In some cases, the other parent could be a citizen of the U.S. An estimated 275,000 undocumented parents have U.S.-born children ages 18 and older.

The 14th Amendment to the U.S. Constitution states: "All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the state wherein they reside."

On Sunday, Trump came out in support of ending birthright citizenship. The following day, Wisconsin Gov. Scott Walker (R), who has recently seen his 2016 star fade somewhat in the early caucus state of Iowa, joined him. Other Republican presidential candidates -- including Sen. Rand Paul (Ky.) and New Jersey Gov. Chris Christie -- have said the issue needs to be re-examined.

Republicans also oppose Obama administration executive actions providing deportation relief for unauthorized youth who were brought to the U.S. as children. Trump supports rescinding those initiatives, telling NBC on Sunday that young undocumented immigrants "have to go."

Elise Foley contributed reporting.