After Hurricane Maria struck Puerto Rico, resulting in nearly 3,000 deaths, former acting Homeland Security Secretary Elaine Duke said Trump considered selling the US commonwealth.

Trump famously visited Puerto Rico after the 2017 hurricane, and was photographed throwing paper towels into a crowd. He also withheld relief funding. In a separate instance, he suggested buying Greenland.

The New York Times – Leading Homeland Security Under a President Who Embraces ‘Hate-Filled’ Talk
Business Insider – Trump touted selling Puerto Rico after the territory was devastated by a hurricane in 2017, says former official
USA Today – Trump floated idea of selling Puerto Rico after Hurricane Maria, says ex-Homeland Security head Duke