The nation's highest court has decided to hear case disputing citizenship by birth.

The top court has decided to review a landmark case that questions a historic constitutional right: birthright citizenship for those born within US borders.

On his first day in office this winter, President Donald Trump enacted a directive aiming to end birthright citizenship, but the action was subsequently blocked by lower courts after lawsuits were brought forward.

The Supreme Court's eventual judgment will either affirm citizenship rights for the infants of foreign nationals who are in the US undocumented or on short-term permits, or it will end those rights altogether.

Next, the judges will schedule a date to hear oral arguments between the federal government and plaintiffs, which comprise parents who are immigrants and their infants.

A Constitutional Cornerstone

For nearly 160 years, the Fourteenth Amendment has established the principle that every person born in the nation is a citizen, with certain exclusions 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 challenged presidential 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 30 countries – largely in the North and South America – that award instant citizenship to anyone born within their borders.