Every night on Broadway, Tom Felton walks on stage to a roar from the audience. He had expected the reaction to die down after the first week, but it never did.

Almost 15 years after his final appearance as Draco Malfoy on screen, Felton has spent the past 10 months playing the character again in the Broadway production of Harry Potter and the Cursed Child.

I meet the actor in a dressing room at NBC Studios, just off Times Square in New York. He’s just finished a live television appearance and in a few hours will be back on stage for his next performance.

He greets me with a hug and says he is excited to speak to BBC News because his mum and 100-year-old grandfather will see it. His family are some of his biggest supporters – his mum has seen the show five times already, while his dad is due to visit next month.

That support mirrors the enthusiasm Felton has encountered from Harry Potter fans, which he says still surprises him more than two decades after he first played Draco.

“I thought the applause would stop in the first week and it has not.

“It’s very humbling and lovely to know how much the characters still mean to people now and if it brings them to the theatre, that’s the best.”

He is also struck by how many of the fans now approaching him were not alive when the first Harry Potter film was released.

“There are fans that approach me shouting ‘Draco’ who weren’t even born when I was in the first film,” he says.

Felton was the first of the original Harry Potter cast to reprise his role in the theatre show, but he will not be the only one for much longer, as Rupert Grint is set to return as Ron Weasley on Broadway in February.

The 38-year-old actor says he called his former co-star as soon as he heard the news.

“We are typically – and he will agree with me – pretty bad at our phone game, but when I heard the news I called him immediately and I’m so excited for him,” Felton says. “Who doesn’t want to see Rupert Grint play Ron Weasley again? Come on!”

I ask whether Felton offered any advice to his co-star but he laughs and says absolutely not, pointing out that Grint has already appeared on Broadway.

“I don’t think he needs any advice from me. If anything, I would be taking it from him.”

He adds that Grint has a “Ron Weasley laissez-faire approach to these things”.

More than two decades after they first met on the Harry Potter set, Felton says the friendships between the young cast have endured.

He describes Grint, Daniel Radcliffe and Emma Watson as “best mates” and “family”, even if getting them all in the same place is now difficult.

“We are usually in four different corners of the Earth, so it’s hard to get together,” he says, adding that their support since his return to Draco has been “fantastic”.

As Felton and Grint return to familiar roles on stage, a new generation is preparing to take over the characters in HBO’s television adaptation of the books set to air later this year.

Felton recently met his successor, Lox Pratt, and “saw a lot of myself in him”.

Felton says he was struck by Pratt’s confidence and describes him as a “charming young man and fabulous actor”.

Their families have even been in touch.

“My mum is in contact with his mum and I’m encouraging him to be as cheeky as possible – but professional first.”

Felton says he is not worried about the level of scrutiny Pratt and the other young actors may face as they take on some of the best-known characters in popular culture.

“You just enjoy it for what it is.

“I’m not worried about that at all for him. He’s got a very good head on his shoulders and what you don’t know doesn’t hurt you. I’m sure he’s not one to scroll through negative comments.”

Nor does Felton appear concerned that Harry Potter is being adapted again relatively soon after the films.

Instead, he says the longer television format offers the chance to explore parts of the books that the films did not have time for.

“We had two hours to fit in a lot of content and the wizarding world is vast, so it’s exciting to know they can dive in deeper.”

“I hope the fans of the books and films explore more about Draco,” he says.

While some actors might want to distance themselves from the role that made them famous, Felton has embraced his connection to Harry Potter.

He says the franchise has given him “a life I could never have imagined” and that, even today, it is “bringing people together from every corner of the earth”.

Asked whether this really is the last time he will play Draco, Felton is reluctant to rule anything out.

“I suppose I said 15 years ago that was the end of Draco and I was leaving him forever, but here I am.

“It’s hard to say with any certainty what’s to come.”