Neil Diamond has announced he is retiring from touring after being diagnosed with Parkinson's disease.

The veteran singer and song-writer, who turns 77 on Wednesday, said he was cancelling his March tour dates for Australia and New Zealand on medical advice.

“Legendary singer, songwriter and performer Neil Diamond today announced his retirement from touring due to his recent diagnosis of Parkinson’s disease,” a statement on his website confirmed.

Midway through his 50th anniversary tour, Mr Diamond said he had taken the decision to quit touring  "with great reluctance and disappointment".

He added: “I have been so honoured to bring my shows to the public for the past 50 years. My sincerest apologies to everyone who purchased tickets and were planning to come to the upcoming shows.

“I plan to remain active in writing, recording and other projects for a long time to come.

“My thanks goes out to my loyal and devoted audiences around the world. You will always have my appreciation for your support and encouragement. This ride has been ‘so good, so good, so good’ thanks to you.”

Parkinson's is a progressive condition in which the brain becomes damaged. It can lead to tremors, difficulty moving, speech changes and eventually memory problems.

#Neil Diamond So,so sorry to hear about the great Neil Diamond’s illness. I’m rooting for you Neil! Fight on from another Brooklyn boy!

— Barry Manilow (@barrymanilow) January 23, 2018

Mr Diamond has sold over 130 million albums worldwide and is set to receive a lifetime achievement award at Sunday's Grammy Awards.

The singer last performed in the UK and Ireland in October as part of the 50th anniversary world tour, but the onset of Parkinson's disease "has made it difficult to travel and perform on a large scale basis," his official website said.

Friends and fans sent their best wishes to the singer on social media as news of his retirement spread.

So much respect for #NeilDiamond. Feel honored to have seen him live. Wishing him strength and good wishes. https://t.co/hVRWjTZvD8

— Richard Marx (@richardmarx) January 23, 2018

Barry Manilow wrote: “So sorry to hear about the great Neil Diamond’s illness. I’m rooting for you Neil!.”

"Keep fighting, old buddy. You've got a long way to go yet," tweeted singer Nancy Sinatra.