In the world of blockbuster movies, it's not often that fans have to wait two decades for a sequel, but considering Independence Day got its first home release on VHS its follow-up has been a long time coming.

Joining the sequel's cast as a fighter pilot, Aussie actor Liam Hemsworth remembers seeing the original when he was – wait for it – just six years old. Do you feel as old as I do, now? Sure, maybe he shouldn't have been watching a film about swarms of violent aliens hell-bent on wiping out mankind at such a young age, but he recalls being blown away by the action in what was arguably one of the most iconic films of his generation.

Now, in a future that boy could never have predicted, Hemsworth finds himself in the heart of that action as Independence Day: Resurgence explodes back onto our screens.
It wasn't necessarily an easy sell, though.

"I had concerns, initially, when I heard they were going to do a second one. I was like, 'Nah, it's 20 years later. Why would you do that?'" he laughs. But after sitting down with Roland Emmerich – legendary director, co-writer and producer of both films, it became crystal clear that this wasn't just some half-arsed attempt at cashing in on the original, but a project of passion, years in the making.

"Roland told me why he wanted to do another one and the fact that many scripts over the last 20 years had been brought to him that he didn't feel were worth making," Hemsworth says. "And they finally got to a place where he really liked this script and felt confident in it and wanted to make this film."

Picking up two decades after the original movie, Earth is a vastly different place. Reeling from the previous invasion, the military – having harnessed some of the advanced technology from the spacecraft wreckage, have created a global defence programme (Earth Space Defence). The only trouble being that the aliens have also forged ahead with their tech and are thirsty for revenge. The result is an intergalactic battle of gigantic proportions but, like the original film, at its core there's a focus on humanity.

"He [Emmerich] manages to create a great balance in these epic scenarios. Very chaotic, literally out-of-this-world scenarios with very real human relationships," says Hemsworth, a long-time fan of the German filmmaker. "He also told me that the first one was actually one of his favourite projects, his 'baby'. He felt really confident in doing another one, so who am I to tell him differently?"

The film sees the return of many beloved characters: Bill Pullman as the brave and world-weary US President Whitmore, Jeff Goldblum's cynical mastermind David Levinson and even Brent Spiner who played scientist Dr Okun, presumed dead after the first film.

The biggest star of the original, however, will not be back. Will Smith's Captain Stephen Hiller epitomised the drive and patriotism of the US military with just the right amount of swagger. Though his character survived the first invasion, it's rumoured that Smith was reluctant to return having starred in two sci-fi films back to back (After Earth and Men in Black 3) and as a result, Hiller's absence in Resurgence is explained by a heroic yet down-played death by plane crash. Smith's absence left room for a charismatic, heartthrob hero – and that's where Hemsworth steps up as Jake Morrison, a cocky US pilot serving in ESD who lost his parents in the original attack.

I generally don’t take myself too seriously. And I don’t really have a big ego about things

"He's a little bit more outspoken than I am," Hemsworth says, breaking down his character. "And certainly more of a rule-breaker. His ego is a little bigger than mine. I don't really take myself too seriously. I don't really have a big ego about things. We begin the film with him being a forklift driver on the Moon. And because his ego gets in the way, he ends up making a bad decision."

As in the original film, Resurgence places an emphasis on human versus alien technology. Hemsworth may play a pilot but he didn't get the opportunity to fly a fighter jet during filming, though he says he is desperate to get in the cockpit of an F-16. In any case, the planes that were on set were based on hybrid-alien technology so there was little preparation he could do for the role except striving for peak, action-hero fitness.

"The physical part of it was more just about being athletic and functional and generally healthy," he says. "I didn't have to lift anything heavy or do too much of anything like that. I was just doing lots of high-intensity workouts and eating lean and healthy."

It's hard to imagine this being much of a stretch for the 26-year-old, best known for his role as Jennifer Lawrence's love interest hunter Gale Hawthorne in The Hunger Games. His character may not have plumbed emotional depths, but four blockbuster instalments of Hemsworth hunting, fighting and pining over J-Law's Katniss racked him up a formidable fan base. So with teen pin-up status firmly cemented, the aim of Independence Day: Resurgence is surely one of elevation; it's a launch pad for bigger, better roles.

Liam Hemsworth Independence Day: Resurgence

Despite his impressive physical condition, it appears Hemsworth is not in fact infallible, and may be keen to consider a less strenuous role for the sake of his health. Having been a keen surfer his whole life, he recently suffered a bulged disc in his lower back and admits that for much of January and February this year he was unable to move, needing two epidurals.

"One doctor was telling me I was going to have to have surgery so I started seeing another doctor who is more about fixing it the natural way, which is what I want," Hemsworth reveals. "And I'm 100 times better since seeing him and should be fully recovered in the next couple of weeks. But I haven't been able to surf for three months, and I haven't really been able to work out much."

To the eyes of the casual observer, Hemsworth could easily pass for a born-and-bred American lad, especially now that he's been cast in the follow-up to such a patriotic film. But make no mistake: Hemsworth is still an Aussie at his core.

Born to an teacher mother and social worker father, he is the youngest of three brothers – Luke being 35 and Chris 32. Phillip Island, where they grew up, is a wild idyllic backwater in Victoria and not the kind of place film stars are generally made, and yet the Hemsworth clan somehow ended up with three. They all cut their teeth on Australian soaps – something eldest brother Luke kicked off with a stint on Neighbours.

While they are all considered successful in Hollywood terms – definitely by Philip Island terms – globally, Chris is by far the biggest star. From his critically acclaimed turn as James Hunt in Rush to box office belters like Star Trek and as Thor in the Marvel movie series, the middle Hemsworth is a bona fide Hollywood player. It's easy to imagine friendly sibling rivalry boiling over into a full-blown family feud, but it appears the brothers are much closer now than they were in their youth.

"Me and Chris, when we were kids, we didn't get along very well," Hemsworth reflects. "I always looked up to my brothers and wanted to be hanging out with them and their friends. I never had any issues with Luke because he was eight years older and at the time just seemed so much bigger and stronger so I just thought, 'I'm not going to mess with him. I don't need to mess with him.'

"But me and Chris, we're both so like-minded and stubborn that we would constantly fight for whatever we thought was right. And I was the devil child. I was a naughty little kid. I had a real temper and I would throw tantrums all the time and chase Chris with brooms and throw knives at him – all kinds of horrible shit!"

It would be really fun to make a movie with my brothers, but we’d mess around the whole time

He remembers a time when his parents went overseas for a few months, leaving him and Luke in the care of their grandparents while Chris stayed with an uncle. Quite simply, all three boys were too much to handle and couldn't be together without fighting.

In 2009, with their sibling rivalry firmly behind them, Liam and Chris moved to Los Angeles with hopes that their moderate success in Australia would open doors in Hollywood. The cutthroat film industry is tough enough for any young actor, but for Hemsworth the fiercest competition was to come from within his own family – especially when it transpires that Liam was first approached by Kenneth Branagh to screen test for Marvel monster Thor, but the part eventually went to big brother Chris.

Fatefully, that same week Disney called Hemsworth with the news that they had chosen him to star as the lead in the adaptation of Nicholas Sparks' teen romance novel The Last Song. The film was a saccharine – OK, some might say cheesy – affair and can now be found lurking in the lighter categories on Netflix, but his undeniable teen appeal and blossoming relationship with – and subsequent engagement to – co-star Miley Cyrus massively boosted his popularity, leading to him being cast in The Hunger Games and setting him on the road to superstardom.

Since The Last Song, Hemsworth's career has been on a strong and steady incline. His relationship with Cyrus, however, has been more complex. When the couple began dating it was a media dream: two wholesome young celebrities, deeply in love onscreen and off. But their union has been stormy to say the least and no-one needs reminding what Cyrus has been up to over the last four years, shedding her squeaky clean Disney persona with literally too many naked photo shoots to count, coupled with controversially sexual on-stage antics and some admirable activism on behalf of the LGBTQ community. It remains to be seen whether they will end up together – currently the engagement appears to be on, but at that level of celebrity, nothing is confirmed unless it comes direct from the couple.

While the Cyrus effect has certainly made him a regular in the tabloids, it now remains to be seen whether or not Hemsworth can cut the mustard as a serious actor. Unlike his brother Chris, he hasn't yet had his Rush moment of cinematic glory. All too often he is cast as the eye candy – as proven in last year's Australian comedy-drama The Dressmaker where he played the sex object opposite Kate Winslet; one scene saw Hemsworth in just his pants while Winslet was fully clothed in a minor Hollywood role reversal.

The Aussie wasn't fazed. "Everyone is laughing, so it's pretty fun. You feel like an idiot because you're the one guy in the room that's sitting there in his underpants. But it's fun for everyone else!"

All jokes aside, it feels like now is the time for Hemsworth to step out of the shadows and lay claim to his place in cinema history. Could Independence Day: Resurgence be the kind of box office monolith that could do just that? Only time – and the reviews – will tell.

While Hemsworth's transition to the big leagues rests on this movie, one project he would love to see realised is a film involving all three brothers. "We joke about it all the time," he smiles. "It would be really fun to do. I'd love to work with my brothers. It would be hard to do, because we'd just be messing around the whole time. But I don't think it's going to happen any time soon, realistically."

From the Australian outback to the Hollywood Hills, Hemsworth has never dreamt small, so it makes sense that after Resurgence, he is gunning to work with the biggest director in the world right now: "The guy who did The Revenant and Birdman [Alejandro González Iñárritu]. That's some of the most amazing filmmaking I've ever seen," he grins. "So, obviously, yeah: the guy who's been bagging all the Oscars!"

Independence Day: Resurgence is out in cinemas now: