Sir Tom Jones announced Saturday that he is postponing his U.S. concert tour, which was scheduled to begin next week, because of health issues.
The 77-year-old said he came to the decision after receiving "medical advice." Jones, however, did not elaborate on the state of his health or provide further details.
In his tweet, Jones sent his "sincere apologies" to fans who had purchased tickets for the upcoming tour. A statement on the singer's website said the tour will be rescheduled for May and June of next year and tickets for the postponed shows will be honored.
His U.S. tour was scheduled to begin Sept. 6 in Pennsylvania.
The Welsh crooner has enjoyed a long career that began in the 1960s with his hits "It's Not Unusual" and ''What's New Pussycat."
The sudden postponement prompted numerous concerned fans to wish Jones well on Twitter.
Dear, dear Tom so very sorry. Praying for a speedy recover because you are so loved by me and so many.— JanieB (@ldslady65) September 1, 2017
Awww! You've had a busy few months so it's the best thing to do Tom so take care x lots of love xxx— Wendy (@WendyBo62172127) September 1, 2017
I'm heartbroken. But please get better. Love always— Kathy Strittmatter (@kathys533) September 1, 2017
The Associated Press contributed to this report.