HE enjoys fame and success, but Hollywood star Will Smith constantly reminds himself that family is more important than big box office or winning awards.

The star of Men In Black, Independence Day and Ali is surrounded by his family as he says this – actress wife Jada Pinkett Smith, and 12-yearold son Jaden. Only daughter Willow is missing from the family line-up.

The Smiths are in London for the UK premiere of the remake of Seventies classic movie The Karate Kid, already a hit in the US.

Smith doesn’t appear in the movie, but son Jaden does, starring in the title role of the boy who takes up kung fu to beat school bullies after his mother’s work sees them moving to China. Jackie Chan co-stars as the maintenance man who teaches the kid to stand up for himself.

Jaden’s parents were producers on the movie, on hand on location in China to keep an eye on their son.

Jada says they knew they had to participate in the movie in some way.

“We have so much knowledge between the two of us that we want to pass on to our children. So we really felt it was important to us to participate first-hand as far as this project was concerned,” she explains.

“And so we really felt we had to be there as mommy and daddy, and as producers, just to make sure Jaden was taken care of, because this was a big, big, big endeavour for him to take on. We wanted to support him in every way possible.”

Smith, unused to having to take a back seat, assumes the role of proud father of Jaden, the son with whom he previously appeared on screen in The Pursuit Of Happyness “I know it was excruciating for Jaden to be squashed particularly between Jackie and myself,” says Will.

“There was a real struggle for Jada and Jaden to try to keep the pressure off. He’s so disciplined and so hardworking that it’s hard not to push him for more.

“He’s such a fantastic, disciplined young man. He’s really sensitive, so he can capture emotion. And he has the mentality it takes to bear the weight of what the success this film is going to bring in his life.”

Jaden takes all this in his stride, remaining composed and a young man of few words at the press conference.

Like any 12-year-old, he looks like he’d rather be outside with youngsters his own age rather than facing reporters and photographers.

He doesn’t even moan about the training required for the role. “In the movie I did a lot of kung fu and martial arts and everything, but I had a lot of training before so it wasn’t as hard as I thought it would be.

“I thought I’d be out in the snow doing push-ups and stuff like that. It wasn’t like that. I trained for all of it, so I could do it better and all of the kung fu martial arts just came to me, and I could almost have fun when I was filming.”

THE talk turns to family again.

“I have my 12-year-old son that we’ve pushed really hard to achieve, and every day I had to remind myself – well, Jada had to remind me – that the family has to be first,” says Will.

“We have to consider our family first and the project has to be second, which is really difficult because the way that I’ve been able to create the things the way I wanted them to happen is nothing gets in the way.

“I did Ali with a broken thumb. It was like, ‘let’s just pack the glove up a little tighter’. That’s my mentality.

I don’t know how you win if you’re not willing to gamble everything and possibly lose everything when you’re out there.”

The $56m opening in the US for The Karate Kid was bigger than any of Will’s movies, other than Hancock and I Am Legend.

“I’m wondering if he still needs to even live at our house,” he jokes. “If one more person calls me the Karate Kid’s dad...”

Jada points out that one advantage Jaden has over other child stars is that his parents really understand the industry.

“When your dad is still the biggest movie star in the world, it keeps everything really grounded,” she says.

“Jaden grew up in this industry so it’s not foreign to him. He understands that this is a family business, it’s our business and he’s not coming into something new or different.”

Will turns to his son, sitting silently during his parents’ exchanges, and asks, “How are we doing parenting wise, do you feel?”. Jaden seizes the opportunity, saying he should be allowed to stay out longer.

His father points out that he’s allowed out until 10.30pm sometimes, but suggests making a deal, asking what would be a good time for him to come home.

“Like Jada and you have to, be back by three in the morning,” suggests Jaden, pushing his luck. Jada is quick to reply. “Absolutely not.”

Even being the star of one of the most successful movies of the year can’t stay out later than his parents say.

■ The Karate Kid (PG) is now showing in cinemas.