Nickelback has been forced to cancel the remainder of their 2015 "No Fixed Address" North American tour due to a medical emergency.

Lead singer Chad Kroeger has been diagnosed with an operable cyst on his voice box and is set to undergo surgery in three weeks, the band announced on their website. Doctors expect a full recovery but have ordered that the singer remain on vocal rest for some time following the surgery.

All ticket refunds will be available to buyers at the point of purchase, the website announcement says.

A few days ago, the band cancelled their weekend shows hoping that it would give the 40-year-old Kroeger enough time to rest up his vocal chords, but the injury turned into a much more serious diagnosis.

"I am sorry I have to interrupt the party this summer and I am definitely not thrilled with the prospect of being silent for many weeks to come when I could be out there playing for our fans," Kroeger told E! News in a statement. "I am relying on my doctor and his team to help get my voice back in good form as quickly as possible."

Band members Mike Kroeger and Ryan Peake revealed the news in a video on the site as well.

They will resume their tour for its European run in Finland on September 30. They are set to start touring in North America again in 2016.