LOS ANGELES (Reuters) - Three people born in American Samoa have sued the U.S. government, saying that its failure to grant them birthright citizenship violates the 14th Amendment of the Constitution and renders them “second-class Americans.”

The lawsuit, filed in U.S. District Court in Utah, where all three of the plaintiffs live, asks that all people born in American Samoa be granted citizenship and its attendant rights as well as new passports reflecting that status.

American Samoa, an archipelago in the South Pacific Ocean with a population of about 55,000, has been an unincorporated U.S. territory since 1900.

It is the only overseas U.S. territory without birthright U.S. citizenship. Its people are considered noncitizen U.S. nationals, a status that denies them the full rights of American citizenship.

The plaintiffs also seek to have the U.S. Department of State policy declaring them “no-citizen nationals” ruled unconstitutional under the 14th Amendment, which grants citizenship to anyone born in the United States or its territories.

“For plaintiffs, like other Americans born in American Samoa, the Fourteenth Amendment’s promise of equality has not been fulfilled,” the lawsuit says.

“They have been subjected to a stamp of inferior status that diminishes their standing in their communities in our nation as a whole,” the lawsuit states. “This arbitrary and discriminatory constitutional indignity inflicts irreparable and continuing harm on plaintiffs.”

A spokeswoman for the State Department, Pooja Jhunjhunwala, declined to comment, citing a department policy on pending litigation.

In 2015 the U.S. Court of Appeals for the District of Columbia Circuit ruled against a similar challenge to the State Department policy by five American Samoans, finding that the 14th Amendment does not automatically extend to unincorporated U.S. territories like American Samoa.

The U.S. Supreme Court refused to take up the case, leaving that ruling intact.

The U.S. Congress previously has decided on a territory-by-territory basis whether people born in the various overseas territories including Puerto Rico, Guam, the U.S. Virgin Islands and the Northern Mariana Islands automatically become U.S. citizens.

Citizenship would make the plaintiffs eligible for full U.S. passports and such rights as being able to vote in national elections if they reside in a U.S. state.

Those born in the territory can claim citizenship if, at birth, one of their parents was a U.S. citizen. They can also pursue naturalized U.S. citizenship.

The government of American Samoa has opposed birthright citizenship, saying that it might threaten Samoan cultural traditions.