US Supreme Court will hear lawsuit disputing automatic citizenship for those born in the US.

The nation's highest court has will hear a significant case that challenges a longstanding guarantee: birthright citizenship for those born in the United States.

On day one in office this winter, the President signed an order aiming to terminate the policy, but the move was halted by the judiciary after constitutional questions were filed.

The Supreme Court's eventual ruling will ultimately support citizenship rights for the infants of foreign nationals who are in the US illegally or on temporary visas, or it will end the provision altogether.

Next, the court will schedule a date to hear the case between the federal government and the suing parties, which involve foreign-born parents and their young children.

A Constitutional Cornerstone

For more than 150 years, the 14th Amendment has codified the doctrine that every person born in the United States is a US citizen, with certain exclusions for children born to foreign 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 challenged directive sought to refuse citizenship to the children 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 among about a minority of states – largely in the Americas – that grant instant citizenship to anyone born within their borders.