US Supreme Court agrees to consider legal challenge questioning citizenship by birth.

The nation's highest court has decided to review a landmark case that questions a century-old principle: birthright citizenship for people born within US borders.

On his first day in office this January, President Donald Trump signed an order aiming to end this practice, but the order was subsequently blocked by lower courts after lawsuits were filed.

The Supreme Court's eventual ruling will ultimately uphold citizenship rights for the offspring of immigrants who are in the US without authorization or on short-term permits, or it will nullify those rights entirely.

Next, the judges will set a time to hear oral arguments between the administration and the suing parties, which comprise foreign-born parents and their newborns.

The 14th Amendment

For over a century and a half, the Constitutional amendment has enshrined the principle that every person born in the nation is a citizen, with specific conditions for children born to foreign diplomats and members of foreign military forces.

"Every individual 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 deny citizenship to the offspring of people who are whether in the US illegally or are in the country on temporary visas.

The United States is among about 30 countries – mostly in the Americas – that provide instant citizenship to anyone born on their soil.