The nation's highest court has decided to review lawsuit questioning citizenship by birth.

The US Supreme Court has will hear a landmark case that challenges a longstanding constitutional right: automatic citizenship for individuals born in the United States.

On his first day in office this winter, President Donald Trump signed an order aiming to halt this practice, but the move was halted by lower courts after lawsuits were initiated.

The Supreme Court's final judgment will ultimately support citizenship rights for the offspring of foreign nationals who are in the US without authorization or on temporary visas, or it will nullify the provision entirely.

Next, the court will schedule a date to hear oral arguments between the federal government and the suing parties, which involve parents who are immigrants and their young children.

A Constitutional Cornerstone

For more than 150 years, the Fourteenth Amendment has enshrined the rule that every person born in the country is a American citizen, with exceptions for children born to foreign diplomats and personnel of foreign military forces.

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

The contested presidential order sought to refuse citizenship to the children of people who are either in the US illegally or are in the country on temporary visas.

The United States belongs to a group of about three dozen nations – largely in the Americas – that award instant citizenship to any person born within their borders.