The world's press are gathered at a news conference for Luc Besson's "Valerian and the City of a Thousand Planets" and Dane DeHaan is waxing lyrical about co-star Cara Delevingne.

The pair spent six months in Paris filming as intergalactic special ops agents Valerian and Laureline in the $180 million blockbuster, which comes out Friday, and DeHaan was clearly bowled over by Delevingne's infectious joie de vivre. 

"I was just so happy to see her every day and be around her and feed off that energy," DeHaan told reporters at the event in Beverly Hills.

It sounds like the usual mutual back-slapping in which actors indulge on promotional tours but he is clearly being sincere, and in any case it is the kind of observation frequently made by people who have worked with the 24-year-old Londoner.

One of the world's most in-demand models, Delevingne has earned millions of dollars walking the runways of London, Paris and Milan for the likes of Burberry and Chanel, and graced countless covers of Vogue. 

But acting has always been her first love.

Her rise in movies since her debut in Joe Wright's "Anna Karenina" (2012) alongside Keira Knightley has been swift, with starring parts in teen fable "Paper Towns" and the super-villain blockbuster "Suicide Squad."

- Role model -

Making the transition into acting when you are already well-known is not as easy as it looks. Former sports stars and other celebrities often observe that while their famous faces get them auditions, they have to work twice as hard to be taken seriously.

Two years ago, Delevingne appeared on a local US morning talk show to promote "Paper Towns" and was asked a series of patronizing questions, including whether she had read the source novel by John Green. 

Not only had she done her homework, but she has since written a coming-of-age novel of her own.

"There will always be people like that, no matter what," she told AFP in an interview after the news conference.

"I think it's just another opportunity for me to stand my ground and prove I have done the work. I do work very hard and I'm determined to prove those people wrong."

An influential voice on social media with more than 40 million Instagram followers, Delevingne has been praised for being a beacon to teenagers struggling with their emotions by speaking openly about her bisexuality and her battles with depression as a 15-year-old.

"I'm very blessed to have a strong influence with young girls and teenagers," she said.

"That's been my goal since I was younger, to be a role model, for young girls to be able to look up to me, because I'm following every single one of my dreams that I've had in my life through hard work and determination."

- 'Natural born actress' -

When he was casting for the part of Laureline, Besson immediately thought of Delevingne as an actress who could live up to the spirit of empowerment her brave, whip-smart character embodies as Valerian's crime-fighting equal.

"She became a model by accident because a scout guy met her and said, 'You will take good pictures.' But she's not made for that," Besson told AFP.

"She succeeds at that because she's funny but for me she's a natural born actress. I was amazed by her capacity and I think she's at the beginning of a long, long career." 

Critics have observed that the character of Laureline is something of a paradox -- an intrepid, independent woman who nevertheless defines her happiness in terms of her success in finding love.

"That's what I love about life generally, the dichotomies of everything. Of course I understand the whole thing of wanting to be a woman who can look after herself and be completely independent," Delevingne told AFP.

"But also, at the end of the day all I want is to go home and have someone that loves and cares for me or that I love and care for and end up one day having a family."

Laureline, she says, embodies the new reality that romance is no longer the zero sum game it once was for women, pitting family life against the possibility of a career.

"I do relate to her in the sense that I, for sure, am strong and independent and all these things, but at the end of the day, I'm a complete hopeless romantic," she said. 

"Some people deny it, but aren't we all?"