Singer Neil Diamond on Monday announced he is retiring from concert touring because it had become “difficult to travel and perform” after he was recently found to have Parkinson’s disease. In a statement on his website, the Rock and Roll Hall of Famer offered his “sincerest apologies” to those who planned to attend his shows in Australia and New Zealand in March. The concerts, part of his 50th anniversary tour, have been canceled on his “doctors’ advice,” the statement read. Diamond, known for hits such as “Sweet Caroline,” has vowed to continue to write and record music “for a long time to come” despite the illness. “It is with great reluctance and disappointment that I announce my retirement from concert touring. I have been so honored to bring my shows to the public for the past 50 years,” Diamond said.