Nicole Kidman has finally ended months of speculation by revealing that country singer Keith Urban is actually her fiance.

The actress brought Urban along as her date to the 30th anniversary gala for charity UNIFEM on Saturday, and when asked about the event on Monday by People magazine she replied: "He's actually my fiancé. I wouldn't be bringing my boyfriend."

The couple were first spotted together in July 2005, but the rumours started in November when the Oscar winner was snapped wearing a large diamond ring on her ring finger.

The actress joined UNIFEM a few months ago after hearing about it from her mother.

"My mother heard a program on the BBC about what they were doing in Cambodia, and she taped it," Kidman told the publication. "She knew I was looking for something that I can get behind. She told me about the work they were doing, they were giving choices to women. They were doing something rather than just saying, oh this is so dire."