The 26-city trek was scheduled to kick off next month in Quebec and run through the summer.

The singer was admitted to the hospital last month after suffering a severe asthma attack. Doctors diagnosed him with acute respiratory failure and told him last weekend that he needs to rest and not work for a period of at least six months or he could suffer further complications.

Anderson apologized to fans and expressed his feelings about the cancellation in a statement.

“In the wake of my recent respiratory attack, doctors have advised me to spend the coming months resting and recovering. Unfortunately, this means I won’t be able to tour with Yes this summer as originally planned.

“I’d like everyone to know how deeply disappointed I am by this turn of events. I was looking forward to celebrating our music with the amazing family of Yes fans once again; but as we all know, health must come before anything else.”

Ticket refunds will be available at point of purchase.