Celine Dion's "Courage World Tour" dates through 2024 have been canceled as she continues to battle a rare neurological disorder, it was announced Friday.

"I'm so sorry to disappoint all of you once again," an announcement on the singer's social media read. "I'm working really hard to build back my strength, but touring can be very difficult even when you're 100%. It's not fair to you to keep postponing the shows, and even though it breaks my heart, it's best that we cancel everything now until I'm really ready to be back on stage again. I want you all to know, I'm not giving up... and I can't wait to see you again!"

Dion postponed several shows in December after she announced she had been diagnosed with stiff-person syndrome, a condition, she said, that doesn't allow her "to sing the way I'm used to."

The disorder is "a rare, progressive syndrome that affects the nervous system, specifically the brain and spinal cord," according to the National Institute of Neurological Disorders and Stroke.

"While we're still learning about this rare condition, we now know this is what's been causing all of the spasms that I've been having," Dion said at the time. "Unfortunately, these spasms affect every aspect of my daily life, sometimes causing difficulties when I walk and not allowing me to use my vocal cords to sing the way I'm used to."

Tickets for her concerts will be refunded from their point of purchase.