US Supreme Court has decided to hear lawsuit disputing automatic citizenship for those born in the US.

The nation's highest court has decided to review a pivotal case that questions a century-old constitutional right: guaranteed citizenship for individuals born within US borders.

On day one in office this January, President Donald Trump signed an order aiming to end the policy, but the move was subsequently blocked by lower courts after lawsuits were brought forward.

The Supreme Court's final judgment will either affirm citizenship rights for the children of immigrants who are in the US undocumented or on short-term permits, or it will end those rights completely.

Next, the justices will calendar a session to hear oral arguments between the federal government and plaintiffs, which include immigrant parents and their newborns.

A Constitutional Cornerstone

For nearly 160 years, the Fourteenth Amendment has enshrined the principle that every person born in the nation is a American citizen, with certain exclusions for children born to diplomats and personnel of invading forces.

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

The contested presidential order sought to withhold citizenship to the children of people who are either in the US in violation of immigration law or are in the country on non-permanent visas.

The United States is among about a minority of states – largely in the Western Hemisphere – that provide instant citizenship to all those born on their soil.