America's top judicial body will consider case questioning citizenship by birth.

The nation's highest court has will hear a landmark case that questions a century-old guarantee: automatic citizenship for those born on American soil.

On day one in office this winter, the administration enacted a directive aiming to end birthright citizenship, but the order was subsequently blocked by lower courts after legal challenges were filed.

The Supreme Court's eventual judgment will ultimately uphold citizenship rights for the infants of migrants who are in the US without authorization or on short-term permits, or it will end those rights altogether.

Next, the court will schedule a date to hear arguments between the administration and claimants, which involve parents who are immigrants and their newborns.

A Constitutional Cornerstone

For over a century and a half, the Fourteenth Amendment has enshrined the doctrine that every person born in the country is a citizen, with specific conditions for children born to foreign diplomats and personnel of occupying armies.

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

The contested executive order sought to refuse citizenship to the children of people who are either in the US illegally or are in the country on non-permanent visas.

The United States is one of about a minority of states – mostly in the North and South America – that grant immediate citizenship to all those born in their territory.