America's top judicial body will review lawsuit disputing citizenship by birth.

The nation's highest court has will hear a pivotal case that challenges a century-old guarantee: birthright citizenship for people born in the United States.

On day one in office this winter, President Donald Trump issued an executive order aiming to halt this practice, but the action was halted by federal courts after lawsuits were brought forward.

The Supreme Court's ultimate decision will either support citizenship rights for the children of foreign nationals who are in the US undocumented or on non-immigrant visas, or it will overturn the provision entirely.

Next, the justices will calendar a session to hear the case between the government and the suing parties, which comprise foreign-born parents and their infants.

A Constitutional Cornerstone

For over a century and a half, the Fourteenth Amendment has codified the rule that anyone born in the country is a citizen, with exceptions for children born to foreign diplomats and members of foreign military forces.

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

The disputed directive sought to withhold citizenship to the offspring of people who are whether in the US in violation of immigration law or are in the country on temporary visas.

The United States is among about a minority of states – mostly in the North and South America – that grant automatic citizenship to any person born in their territory.