The Organization of American States says that Nicaragua's elections chief has agreed to resign as part of efforts to reform the country's electoral system.

Roberto Rivas had held the top post on Nicaragua's Supreme Electoral Council for more than a decade. Many accused him of orchestrating electoral frauds that kept President Daniel Ortega in power.

In December, the United States added Rivas to its list of corrupt actors under the Magnitsky Act, barring his access to the U.S. financial system. It said Rivas had amassed a fortune that afforded him multiple properties, private jets, luxury vehicles and a yacht despite his official salary of $60,000 per year.

The OAS statement Thursday said Rivas' resignation was part of its work with Nicaragua to guarantee free and fair elections.