Michael Buble's three-year-old son is diagnosed with cancer

The Canadian singer says he and his wife are "devastated" and will put their careers on hold to help their son Noah get well.

Michael Buble has said his three-year-old son, Noah, has been diagnosed with cancer and is undergoing treatment.

 The singer wrote on his Facebook page that he and his wife, Luisana Lopilato, are "devastated" at the news.

 He asked the public to respect the need for privacy for him and his family.

 "We have always been very vocal about the importance of family and the love we have for our children," the musician wrote on Facebook.

"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 type of cancer has not been disclosed.

Buble and Lopilato, an Argentine model and actress, got married in 2011 and welcomed Noah in August 2013.

The couple also have another son, nine-month-old Elias.

The 41-year-old Buble has recently spoken of how much he loves being a father.

"The only regret that I have in my life is that I took this long to have kids, because I had no idea the perspective it would give me," he told on ITV's Loose Women.

"I had no idea how much I would love being a dad. That's it, that's all I care about."

He added: "I love them too much probably, if there was such a thing.

"It's made everything else so insignificant."

The Grammy Award-winning artist has been announced as the host of the annual Brit Awards ceremony in February 2017.