It is not clear when the Knavs couple obtained their green cards, though their status as permanent residents was first revealed by Wildes in February.
Melania Trump, the 48-year-old first lady, was their sponsor, Mt Wildes told the Times.
Under US law they must have been permanent residents for five years before applying to become citizens, and the time to process an application can take several months thereafter.
Viktor Knavs, a car salesman in Slovenia, and Amalija, who worked in a textile factory, are over 70 years old, retired and pass much of the year in the United States, where they regularly spend time with their daughter and grandson Barron.
Credit: The Telegraph