Bangladesh, Dec. 21 -- The United States has imposed new travel restrictions on Dominica and Antigua and Barbuda, escalating Washingtons campaign against citizenship-by-investment programs that it views as security liabilities. Announced by President Donald Trump on December 16, the move places the two Caribbean nations on an expanding US travel ban list that now covers 39 countries and signals a deeper shift in how Washington intends to police the global trade in passports.

Beginning in January, holders of Dominican and Antiguan passports will face restricted entry into the United States. A White House proclamation cited what it described as long-standing vulnerabilities in the two countries citizenship-by-investment programs-often call...