Australia is in the midst of winter, but you wouldn't know it if you were at Bondi beach today.

And if you were at Bondi, you may have run into stars Margot Robbie, Greta Gerwig, Issa Rae and America Ferrera, who are Down Under promoting the upcoming film Barbie.

The quartet appeared at a press conference at Bondi Icebergs Club ahead of the fan event at Westfield at Pitt Street Mall tomorrow.

Gerwig, who is the director of the new film, referenced Tom Cruise who tweeted this morning that 'this summer is full of amazing movies to see' in theatres – including Barbie.

Gerwig expressed her glee.

"Barbie is in there with all the movies," Gerwig said.

Robbie is the film's star and she's also a producer on the movie. She said it's important for Barbie to do well, so the next story that comes along with strong female leads also gets a chance at getting off the ground.

"Obviously I want the movie to do well because we all worked so hard, and we love it so much," Robbie said.

"But I think it is important when a movie like this does do well.

Robbie said there were few comparisons she could cite when pitching the concept of Barbie.

"I remember when they were trying to come up with comps for this movie and there's not that many," she said.

"And it's important to have them. It makes a difference on the business side of things to have those comps and have the proof in the pudding that they've made money."

Gerwig said when Robbie approached her to make the film, it sounded like a great idea.

"I feel very grateful that Margot came to me almost four years ago and said, 'do you want to write a Barbie thing?' And I'm grateful that in my postpartum days of four years ago, I said yes."

Robbie had been keeping a keen eye on Barbie's intellectual property.

"I was aware that the Barbie IP was floating around," Robbie said.

"So, we've been keeping tabs on the property. And when there seemed like there was an opening, we kind of jumped at the opportunity."

Barbie will hit cinemas in Australia July 20