Celine Dion vowed Monday her "passion as a performer will never disappear," despite health struggles she says are still just a small part of her monumental story.

"I'm not dead," the singer told AFP on the red carpet, ahead of the premiere of the both wrenching and joyful documentary "I Am: Celine Dion".

The movie focuses on her soaring career and more recent challenges with a rare neurological disorder that has drastically hampered her ability to perform.

"When life imposes something on you, you have two options. You deal with it or you don't want to deal with it," Dion said.

She called her decision to speak out about her condition in the documentary both "the greatest gift and the greatest responsibility," saying she hoped it would inspire people with similar obstacles.

At one point ahead of the premiere the Quebec-born star switched to her native French, telling journalists that "it's hard to be here. But at the same time, I'm so moved."

"I feel that I still have a lot of support and a lot of love and I hope this documentary will help, because it helped me a lot," she said, detailing her gratitude to her family, her medical team and her fans.

"Even if it's a forever fight, one day at a time."

'Authentic'

The 56-year old first disclosed in December 2022 that she had been diagnosed with Stiff Person Syndrome, a progressive autoimmune disorder with no cure.

She was forced to cancel the remainder of her shows indefinitely.

Treatment can help alleviate symptoms of the condition that can cause stiff muscles in the torso, arms and legs.

Overstimulation can also trigger severe spasms, and can cause her voice to crack uncontrollably.

"The show will still go on," she promised, but said it was important to be honest about the physical and emotional intensity of her condition.

Irene Taylor, the Academy Award-nominated director behind the film, told AFP that Dion's one ask was to be able to tell her own story, in her own words.

"Would that be possible? Instead of other people talking about me?" she recalled the superstar requesting.

"That was like music to my ears as a storyteller," Taylor said.

"She just opened up and was very authentic," the director continued. "In her joy, and also in her suffering."

'Love letter'

The intimate film features archival footage of the charismatic performer the world knows and loves, as well as tender scenes at home with her children and dogs that lend a quirky, cozy portrayal of Celine as a parent.

But the film also documents the severity of Dion's pain, including one lengthy sequence that shows with excruciating detail the singer suffering from a seizure, which renders her not only immobile but unable to speak.

The devastating episode left some in the screening audience audibly crying.

But the throughline of the documentary is less Dion's illness as it is her love for her family, friends and music.

She is visibly tormented by the loss of the voice she once knew, but it's her joy in life and an unshakeable sense of humor that shine through in the film.

The documentary about Dion -– who has sold more than 250 million albums throughout her decades-long career –- will begin streaming globally on June 25 on Prime Video.

Earlier this year Dion made a surprise appearance at the Grammy Awards, presenting the Album of the Year award to Taylor Swift.

But she has rarely appeared publicly since announcing she had SPS.

Speaking to the packed, enthusiastic hall in Manhattan ahead of the screening, Dion compared herself to an apple tree.

She also makes the metaphor in the film, saying that she's always felt she must produce shiny fruit for fans who were willing to pay large sums and wait in long lines for her performances.

Dion was moved to tears as she described a comment from a recent fan, who told her in a message that "we're not here for the apples -– we're here for the tree."

"This movie is my love letter to each of you," she said to a standing ovation.

"And I hope to see you all again very soon."