René Angélil and Céline Dion
Willi Schneider/REX USA
has postponed her Las Vegas residency, canceled her Asia tour and postponed all of her show business activities indefinitely because of her husband's ongoing health issues
René Angélil had a tumor removed
from his throat last December, and his illness has caused "a very difficult and stressful time," the singer says in an exclusive statement to PEOPLE.
"I want to devote every ounce of my strength and energy to my husband's healing, and to do so, it's important for me to dedicate this time to him and to our children," Dion tells PEOPLE. "I also want to apologize to all my fans everywhere, for inconveniencing them, and I thank them so much for their love and support."
Dion, 46, is also suffering from inflammation in her throat muscles, which has prevented her from performing her show at Caesars Palace since July 29.
Angélil, 72, and Dion have three young children, René-Charles
, 13, and fraternal twins
Eddy and Nelson, 3½.
Reporting by JENNIFER GARCIA