The Trump administration asked the Supreme Court on Thursday to allow a ban on birthright citizenship in about half of the country for children born to undocumented immigrants and foreign visitors.

On his first day in office, President Donald Trump signed an executive order ending automatic citizenship for children born in the U.S. if neither of their parents is lawfully in the country, a practice enshrined in the 14th Amendment to the U.

The Trump administration is pushing for the the U.S. Supreme Court to allow some restrictions on birthright citizenship even as legal battles continue over President Donald Trump’s orders to end what has long been seen as a constitutional promise.