US Supreme Court will hear legal challenge challenging citizenship by birth.

The top court has decided to review a significant case that challenges a longstanding guarantee: birthright citizenship for people born in the United States.

On day one in office this January, President Donald Trump signed an order aiming to halt this practice, but the action was subsequently blocked by lower courts after legal challenges were initiated.

The Supreme Court's eventual judgment will ultimately uphold citizenship rights for the infants of foreign nationals who are in the US undocumented or on non-immigrant visas, or it will end those rights altogether.

Next, the court will schedule a date to hear arguments between the administration and claimants, which involve foreign-born parents and their infants.

A Constitutional Cornerstone

For nearly 160 years, the Fourteenth Amendment has codified the principle that anyone born in the United States is a American citizen, with certain exclusions for children born to diplomats and personnel of occupying armies.

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

The challenged presidential order sought to deny citizenship to the children of people who are whether in the US without legal status or are in the country on temporary visas.

The United States is among about 30 countries – mostly in the Americas – that grant instant citizenship to all those born on their soil.