By David Schwartz

Kansas and Arizona filed a lawsuit against the U.S. federal government on Wednesday, seeking court approval for states to require proof of U.S. citizenship when registering to vote.

The lawsuit brought by the two Republican-led states accuses an agency of President Barack Obama’s Democratic administration of preventing them from enforcing state laws that require proof of citizenship as a way to prevent illegal immigrants from voting.The suit, part of an on-going battle over voter registration laws being waged nationwide, demands that the U.S. Election Assistance Commission modify federal voter registration forms to allow states to require proof of citizenship.The federal form now asks for a verbal pledge that the applicant is a U.S. citizen but does not require documentation as proof.In June, the U.S. Supreme Court struck down the controversial provision requiring proof of citizenship passed by Arizona voters in a 2004 referendum. The requirement was criticized by immigrant advocacy groups such as the Mexican American Legal Defense and Education Fund.

Read More Arizona and Kansas sue U.S. over voter registration law | Reuters.