UNIFEM Goodwill Ambassador Nicole Kidman speaks at a press conference to discuss the "Say No to Violence Against Women" campaign at UN headquarters in New York. [Agencies]

Oscar-winning Hollywood superstar Nicole Kidman was at the UN headquarters on Tuesday to spearheaded a drive to raise awareness of violence against women.

"One in three women will encounter violence in some way, shape or form against them in their lifetime," said Kidman, the goodwill ambassador for the United Nations Development Fund for Women (UNIFEM).

Kidman, who is visibly pregnant -- seven months so, she said -- held a press conference to kick off the UN-sponsored "Say No to Violence against Women" campaign.

"So much of it is shrouded in silence. What we are trying to do is say this is something that needs to be addressed," said the 40-year-old Australian actress.

"A lot of it is taking away the stigma, creating awareness and not making it a silent pandemic," she added.