Mila Kunis has wowed the crowds at the premiere of her new movie Jupiter Ascending.

The actress showed off her trim waist, just four months after giving birth to baby Wyatt Isabelle, in a strapless black Dolce & Gabbana dress at the Los Angeles event.

[related]Mila, who is currently doing the promotional rounds for her new sci-fi-action movie, made an appearance on The Ellen DeGeneres Show on Tuesday.

While the actress was happy to chat about the joys of motherhood, she refused to be drawn on rumours that she and Ashton Kutcher have tied the knot.

Referencing a Twitter post showing a message drawn in the sand saying: 'Happy New Year, (heart symbol) the Kutchers', Ellen said “so it sounds like you’re married.”

Mila replied: “We could just be a plural. My daughter has his last name legally.”

Mila also revealed that she received a present after delivering her baby girl, who weighed nine and half pounds, but did not reveal the nature of the gift (and whether it was ring-shaped).

“Why would it be such a secret if you were married?” Ellen asked.

“Are you still trying to stay on the market for men... It’s a whole professional thing.”

Mila joked: “You got it figured out Ellen.”

Jupiter Ascending opens in UK cinemas this Friday (6 February).