Georgia Secretary of State Brad Raffensperger has renewed his push for the state Legislature to change the Georgia Constitution to clarify only U.S. citizens can vote in the state.

Raffensperger signed a petition Thursday calling for the constitutional amendment. The petition was created by Americans for Citizen Voting, a national nonprofit advocating for citizen-only voting, to bring awareness to the issue.

Outside a constitutional convention, the only way to amend the Georgia Constitution is by lawmakers introducing an amendment and approving it by a two-thirds vote in both chambers. The amendment then would need to be approved by Georgia voters.

“Only American citizens should be allowed to cast a ballot. We can’t run the risk that special interests one day succeed in giving noncitizens a say in our laws, taxes and representatives the way they have in other states,” Raffensperger said during a news briefing at the state Capitol. “I have worked hard to ensure foreign elements cannot alter our elections through cyberterrorism, so I’m certainly opposed to letting them influence our elections through voting.”

State law already specifies “every person who is a citizen of the United States and a resident of Georgia as defined by law … shall be entitled to vote.” Raffensperger said adding new language to the state constitution would ensure the policy remains in place.

Raffensperger said Georgia experienced isolated incidents of noncitizen voters registering in previous elections, which his office referred to the attorney general for prosecution. Adding clear language to the constitution would close legal loopholes and help the state avoid future lawsuits, he said.

Noncitizen voting in federal elections is illegal across the nation, but some cities are allowing noncitizens to vote in local elections, according to The Pew Charitable Trusts. Atlanta suburb Clarkston, which has a large population of immigrants, has considered allowing noncitizens to vote.

Municipalities in Vermont, California, Maryland and Massachusetts have passed laws allowing noncitizens to vote, Pew said. Raffensperger’s office said Alabama, Colorado, Florida and North Dakota recently have passed amendments by wide margins to provide that only U.S. citizens may vote in local, state and school board elections.

“Voting is a sacred right of citizenship, and it must be strictly reserved for citizens and citizens only,” Americans for Citizen Voting President Christopher Arps said. “No exceptions.”