US Supreme Court agrees to review legal challenge disputing automatic citizenship for those born in the US.

The top court has agreed to take on a landmark case that challenges a century-old guarantee: automatic citizenship for those born on American soil.

On his first day in office this January, the President enacted a directive aiming to halt birthright citizenship, but the order was struck down by lower courts after constitutional questions were initiated.

The Supreme Court's eventual judgment will either uphold citizenship rights for the offspring of foreign nationals who are in the US undocumented or on short-term permits, or it will nullify the provision altogether.

Next, the justices will calendar a session to hear oral arguments between the administration and the suing parties, which comprise parents who are immigrants and their infants.

A Constitutional Cornerstone

For more than 150 years, the 14th Amendment has established the rule that every person born in the country is a American citizen, with specific conditions for children born to foreign diplomats and personnel of foreign military forces.

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

The disputed executive 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 non-permanent visas.

The United States belongs to a group of about three dozen nations – largely in the Americas – that provide instant citizenship to anyone born within their borders.