Singer Michael Buble says three-year-old son Noah has cancer

Canadian singer Michael Buble says he is taking a break from his career because his three-year-old son Noah has been diagnosed with cancer.

"We are devastated about the recent cancer diagnosis of our oldest son Noah who is currently undergoing treatment in the US," Buble said in a Facebook message posted by him and his wife, Argentine model Luisana Lopilato.

"We have always been very vocal about the importance of family and the love we have for our children.

"Luisana and I have put our careers on hold in order to devote all our time and attention to helping Noah get well.

"At this difficult time, we ask only for your prayers and respect for our privacy.

"We have a long journey in front of us and hope that with the support of family, friends and fans around the world, we will win this battle, God willing."

Buble, 41, has sold more than 40 million albums worldwide with his smooth covers of jazz standards and original songs.

He married Lopilato, 29, in 2011. Noah was born in 2013. The couple have a second son, Elias, who was born last January.