US Supreme Court agrees to hear legal challenge questioning birthright citizenship.

The US Supreme Court has decided to review a landmark case that puts to the test a longstanding guarantee: guaranteed citizenship for those born within US borders.

On his first day in office this January, the administration issued an executive order aiming to halt the policy, but the order was halted by federal courts after constitutional questions were brought forward.

The Supreme Court's final ruling will ultimately 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 set a time to hear the case between the administration and claimants, which include foreign-born parents and their young children.

A Constitutional Cornerstone

For more than 150 years, the Constitutional amendment has codified the doctrine that every person born in the country is a citizen, with specific conditions for children born to foreign diplomats and members of invading forces.

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

The disputed presidential order sought to refuse citizenship to the offspring 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 North and South America – that provide immediate citizenship to all those born on their soil.