A lawyer for Viktor and Amalija Knavs revealed the Slovenian couple, who had already been living in the U.S. as permanent residents, took the citizenship oath in New York City.
The First Lady wears an nearly "naked" dress while accompanying her husband to the North Atlantic Treaty Organisation summit. He confirmed that the first lady sponsored their green cards.
Melania Trump's parents have been sworn in as USA citizens. Under the law, permanent residents must live in the country for at least five years before applying for citizenship.More news: Thousands left homeless by deadly quake on Indonesian island
The US allows a number of ways for US citizens and legal permanent residents to sponsor family members to come to the US permanently, including categories for parents, adult siblings and adult children, married and unmarried.
President Trump has railed against family-based or "chain" immigration in the past.More news: Dozens dead in Yemen after school bus carrying children hit by airstrike
The idea that family-based immigration could be labeled as "dirty" might have a lot to do with the Knavs' son-in-law.
Amalija is 73. The first lady, born Melanija, changed her name to Melania Knauss when she started modeling.
While they reside for the most part in New York, AP notes that they've also spent an ample amount of time in the nation's capital helping to take care of their grandson, 12-year-old Barron Trump.More news: Georgia joining North Atlantic Treaty Organisation could trigger awful conflict