The Trump administration is planning to crack down on the practice of birth tourism, where thousands of foreign pregnant women enter the U.S. on a visa, give birth to children who automatically gain American citizenship, and then take the babies back home or to another country, according to three White House officials who spoke with Axios.

The move comes as Trump continues to buckle down on the immigration front – BuzzFeed News last week said the administration has been preparing to expand a travel ban to restrict certain immigrants from entering the U.S.

Trump officials in recent days have also asked the Supreme Court to move forward with a rule that would make it easier to deny legal status to immigrants whose families are deemed likely to use publicly funded programs.

The Center for Immigration Studies, a group that advocates for stricter immigration laws, estimated that in 2012, about 36,000 foreign-born women gave birth in the U.S., then left the country.

Cutting down on birth tourism “is intended to address the national security and law enforcement risks associated with birth tourism, including criminal activity associated with the birth tourism industry," a State Department official told Axios.

Trump has spoken out against the provision in the U.S. Constitution that allows “birthright citizenship” and has vowed to end it, although legal experts are divided on whether he can actually do that.

"Rome wasn't built in a day," the senior official added. "Just the legal recognition that this is improper and wrong and not allowed is a significant step forward."

Information from the Associated Press was used in this report.