The nation's highest court agrees to hear lawsuit questioning birthright citizenship.

The nation's highest court has decided to review a landmark case that puts to the test a historic guarantee: automatic citizenship for people born within US borders.

On the inaugural day in office this January, President Donald Trump enacted a directive aiming to end the policy, but the action was struck down by lower courts after lawsuits were brought forward.

The Supreme Court's eventual judgment will ultimately affirm citizenship rights for the infants of immigrants who are in the US undocumented or on short-term permits, or it will nullify those rights entirely.

Next, the judges will schedule a date to hear oral arguments between the government and plaintiffs, which include parents who are immigrants and their infants.

The 14th Amendment

For over a century and a half, the Fourteenth Amendment has codified the rule that every person born in the nation is a citizen, with exceptions for children born to diplomats and personnel of foreign military forces.

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

The contested directive sought to withhold citizenship to the offspring of people who are either in the US without legal status or are in the country on short-term status.

The United States is one of about three dozen nations – largely in the Americas – that grant immediate citizenship to anyone born on their soil.