BUCHAREST, Romania - Ilie Nastase responded to the backlash from his comments about Serena Williams and his Fed Cup outburst, saying his remarks about the pregnant tennis great were "spontaneous" and his tirade inexcusable.

The 70-year-old tennis Nastase posted a statement on Facebook a week after he speculated about the skin colour of the baby Williams is expecting.

"At the press conference I was asked what opinion I had about Serena being pregnant. I then found out for the first time (she was pregnant) and my reaction was spontaneous," said Nastase, who is the captain of Romania's Fed Cup team.

Nastase also said Williams was "one of the greatest players of all times and I know how much work goes into achieving these results."

Williams is black and her fiance, Alexis Ohanian, is white.

Nastase was also criticized for swearing at player Johanna Konta and Britain captain Anne Keothavong during a Fed Cup match. He said he would not try to "defend my words, but I assure you that behind them was my desire to defend the interests of the Romanian team and Romanian tennis."