US Supreme Court agrees to review lawsuit questioning automatic citizenship for those born in the US.

The top court has will hear a landmark case that questions a longstanding principle: guaranteed citizenship for people born in the United States.

On the inaugural day in office this January, President Donald Trump signed an order aiming to halt birthright citizenship, but the order was halted by federal courts after legal challenges were brought forward.

The Supreme Court's final ruling will either affirm citizenship rights for the infants of migrants who are in the US without authorization or on temporary visas, or it will nullify the provision completely.

Next, the judges will set a time to hear the case between the federal government and claimants, which include parents who are immigrants and their infants.

The 14th Amendment

For more than 150 years, the 14th Amendment has enshrined the doctrine that all individuals born in the nation is a US citizen, with certain exclusions for children born to foreign 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 challenged executive 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 short-term status.

The United States is one of about three dozen nations – primarily in the North and South America – that provide automatic citizenship to all those born within their borders.