President Trump said in a newly released interview he plans to sign an executive order ending so-called "birthright citizenship" for babies of non-citizens born on U.S. soil -- a move that would mark a major overhaul of immigration policy and trigger an almost-certain legal battle.

Birthright citizenship allows any baby born on U.S. soil to automatically be a U.S. citizen.

The policy, which stems from a disputed but long-recognized interpretation of the 14th Amendment, has given rise to what Trump considers abuse of the immigration system. Trump told "Axios on HBO" that the U.S. is the only country in the world "where a person comes in and has a baby, and the baby is essentially a citizen of the United States ... with all of those benefits."

Despite Trump's claim, the U.S. is not the only nation to have birthright citizenship, but the policy is rare outside of the Americas. Trump called birthright citizenship "ridiculous" and said that "it has to end."

Under current policy, anyone born in the U.S. – regardless of whether they are delivered by a non-citizen or undocumented immigrant – is considered a citizen. The interpretation has been blamed for so-called 'birth tourism' and chain migration.

The 14th Amendment 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."

Trump, should he pursue the executive order, would face court challenges, and it remains unclear whether he could prevail. Many legal scholars would argue such a change requires a constitutional amendment. But some conservatives argue the existing amendment holds room for interpretation.

Michael Anton, a former national security adviser for Trump, pointed out in July that "there’s a clause in the middle of the amendment that people ignore or they misinterpret – subject to the jurisdiction thereof.”

"What they are saying is, if you are born on U.S. soil subject to the jurisdiction of the United States – meaning you’re the child of citizens or the child of legal immigrants, then you are entitled to citizenship,” Anton told Fox News’ Tucker Carlson in July. “If you are here illegally, if you owe allegiance to a foreign nation, if you’re the citizen of a foreign country, that clause does not apply to you.”

The interview was released after Trump told Fox News that Central American migrants who are approaching the U.S.-Mexico border in caravans are "wasting their time" and vowed, "they are not coming in."

Trump spoke to "The Ingraham Angle" hours after the Pentagon announced it would deploy some 5,200 troops to the southern border in what the commander of U.S. Northern Command described as an effort to "harden the southern border" by stiffening defenses at and near legal entry points.

"When they are captured, we don't let them out," Trump told host Laura Ingraham. "We're not letting them out ... We're not catching, we're not releasing ... We're not letting them into this country."

Fifth Circuit Court of Appeals judge James C. Ho, who was appointed by Trump, has argued that it would be “unconstitutional” to change how the 14th amendment was written and that the line subject to debate applies to the legal obligation of all foreigners and immigrants to follow U.S. law, Axios reported.

Fox News' Samuel Chamberlain contributed to this report