Kansas and Arizona will get more time to respond to the request by federal election officials for a stay in his ruling requiring them to enforce state laws requiring new voters to document their U.S. citizenship.
U.S. District Court Eric Melgren on Monday gave the states until Friday to file their arguments against his ruling.
In March, Melgren had ordered the agency to immediately modify its national voter registration form to add special instructions for Arizona and Kansas residents about those states' proof-of-citizenship requirements.
The U.S. Election Assistance Commission and voting rights groups want Melgren to stay that ruling while the case goes to the 10th Circuit Court of Appeals.
Both states contend the requirements prevent voter fraud. Critics of such laws view them as suppressing voter turnout.