America's top judicial body will consider legal challenge questioning birthright citizenship.

The US Supreme Court has will hear a pivotal case that challenges a historic guarantee: automatic citizenship for those born in the United States.

On day one in office this winter, President Donald Trump enacted a directive aiming to terminate this practice, but the move was struck down by lower courts after constitutional questions were initiated.

The Supreme Court's ultimate decision will either support citizenship rights for the children of immigrants who are in the US undocumented or on short-term permits, or it will overturn those rights altogether.

Next, the judges will schedule a date to hear oral arguments between the federal government and claimants, which comprise immigrant parents and their infants.

A Constitutional Cornerstone

For more than 150 years, the Fourteenth Amendment has enshrined the principle that every person born in the United States is a US citizen, with certain exclusions for children born to embassy personnel 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 disputed presidential order sought to deny citizenship to the offspring of people who are either in the US in violation of immigration law or are in the country on temporary visas.

The United States is one of about three dozen nations – largely in the North and South America – that award instant citizenship to anyone born on their soil.