The State Department says it is adding 12 countries to an expanding list of nations whose citizens must post bonds of up to $15,000 to apply for U.S. visas. Effective April 2, passport holders from Cambodia, Ethiopia, Georgia, Grenada, Lesotho, Mauritius, Mongolia, Mozambique, Nicaragua, Papua New Guinea, Seychelles and Tunisia will be required to pay the bond, which is refunded if the visa application is denied or, if granted, the person adheres to the terms of the visa. After April 2, there will be 50 countries whose citizens are subject to the requirement, which was rolled out by the Trump administration last year as it cracked down on visa overstays and more broadly moved to curtail illegal migration.