US Supreme Court will hear case challenging birthright citizenship.

The nation's highest court has agreed to take on a significant case that challenges a historic guarantee: automatic citizenship for those born on American soil.

On the inaugural day in office this winter, President Donald Trump issued an executive order aiming to terminate the policy, but the move was subsequently blocked by lower courts after legal challenges were initiated.

The Supreme Court's ultimate ruling will ultimately support citizenship rights for the children of migrants who are in the US without authorization or on non-immigrant visas, or it will nullify those rights altogether.

Next, the judges will set a time to hear the case between the administration and the suing parties, which involve foreign-born parents and their infants.

A Constitutional Cornerstone

For over a century and a half, the Fourteenth Amendment has codified the principle that all individuals born in the nation is a US citizen, with exceptions for children born to foreign diplomats and personnel of occupying armies.

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

The contested directive sought to deny citizenship to the offspring of people who are either in the US illegally 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 provide automatic citizenship to all those born on their soil.