In a phone call after the ceremony, Wildes described the process by which the US First Lady's parents had become US citizens.
Melania Trump's parents were briskly sworn in as citizens of the United States in NY on Thursday (Aug 9).
She had sponsored her parents for their green cards, their lawyer Michael Wildes said in a report in The New York Times. Wildes said the first lady sponsored her parents for their green cards, and once eligible, they applied for citizenship.
Their lawyer said the couple had met the five-year requirement, but added, "I can't give further comment".
President Trump has railed against family-based or "chain" immigration in the past.
It said it is unclear about when or how the couple received green cards.
The plan, which Trump reiterated last week at a Wilkes-Barre, Pennsylvania rally, would limit immigrants like his wife to sponsoring only their spouses and underage children to join them in the U.S. - not their parents, adult children or siblings.More news: Republicans Spent Big to Win a Special Election. Now They're anxious
Later that month, he laid out his immigration plan in the State of the Union address, once again calling for an end to family-based immigration, saying it allows a single immigrant to "bring in virtually unlimited numbers of distant relatives".
The Federal Building also houses immigration court and the local offices of the Department of Homeland Security, and its subsidiary, Immigration and Customs Enforcement.
Asked by the New York Times if the couple had become citizens through "chain migration", Wildes answered "I suppose".
The first lady was born in Slovenia, then part of Yugoslavia, in 1970.
The Knavses' citizenship ceremony was kept hush-hush at the Jacob K. Javits Federal Building.
The Knavses raised Melania in the rural industrial town of Sevnica while Slovenia was under Communist rule. According to news reports, Melania came to the U.S. in 2001 on a so-called Einstein visa for "individuals of extraordinary ability" as a model.