Michael Bublé's three-year-old son has been diagnosed with cancer, the singer and his wife Luisana Lopilato have confirmed.

Noah, who is the couple's eldest child, is currently in treatment in the US.

In a statement on his Facebook page, the Canadian singer said he and his wife - who is an Argentinian actress and model - are "devastated" by the diagnosis.

He writes: "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."

The couple's other son, Elias, was born in January of this year.