The nation's highest court will consider lawsuit questioning birthright citizenship.

The US Supreme Court has decided to review a pivotal case that challenges a longstanding principle: guaranteed citizenship for those born within US borders.

On his first day in office this January, President Donald Trump signed an order aiming to halt this practice, but the action was struck down by federal courts after constitutional questions were brought forward.

The Supreme Court's final judgment will ultimately affirm citizenship rights for the offspring of foreign nationals who are in the US undocumented or on short-term permits, or it will end them completely.

Next, the judges will calendar a session to hear the case between the government and plaintiffs, which comprise parents who are immigrants and their young children.

The Legal Foundation

For more than 150 years, the Constitutional amendment has codified the doctrine that every person born in the country is a American citizen, with exceptions for children born to diplomats and members of foreign military forces.

"All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States."

The contested directive sought to deny citizenship to the offspring of people who are whether in the US in violation of immigration law or are in the country on non-permanent visas.

The United States is one of about three dozen nations – mostly in the Americas – that award automatic citizenship to all those born on their soil.