A Slovenian magazine has apologised to US first lady Melania Trump for suggesting she had worked as a high-end escort while pursuing her international modelling career.

The Suzy women's magazine said it published an article in August 2016 in which it said Trump in the past worked for a fashion agency that also offers an "elite escort" service besides modelling.

It said the article "was understood as if Melania Trump conducted the escort job. We have no proof for that. So we apologise. We had no intention to hurt and offend Mrs. Trump."

Melania Trump has filed a libel lawsuit against the magazine through her Slovenian lawyer.

The 47-year-old left her native Slovenia in her 20s and met Donald Trump in New York in 1998.