Nastase, 71, was unrepentant Monday in an interview with The Associated Press.
"I want to know what word I used is racist?" he asked The AP s by phone on Monday from Budapest, Hungary. He added he was a friend of Williams.
Nastase has been provisionally banned from all ITF events following his verbal abuse of British players last weekend in his role as Romanian Fed Cup captain. He hurled expletives at British player Johanna Konta, Britain captain Anne Keothavong and the umpire. The referee ejected Nastase from the tie.
"Yes, I lost my temper," he said by phone.