America's top judicial body has decided to review legal challenge questioning citizenship by birth.

The nation's highest court has will hear a pivotal case that challenges a historic guarantee: automatic citizenship for people born on American soil.

On day one in office this January, President Donald Trump enacted a directive aiming to halt this practice, but the move was subsequently blocked by the judiciary after constitutional questions were brought forward.

The Supreme Court's eventual judgment will either support citizenship rights for the infants of immigrants who are in the US illegally or on non-immigrant visas, or it will overturn the provision entirely.

Next, the justices will schedule a date to hear the case between the federal government and claimants, which include foreign-born parents and their infants.

The 14th Amendment

For nearly 160 years, the Fourteenth Amendment has established the rule that every person born in the country is a citizen, with specific conditions for children born to embassy personnel and members of occupying armies.

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

The challenged directive sought to refuse citizenship to the children 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 one of about 30 countries – largely in the Americas – that provide instant citizenship to any person born in their territory.