Elton John's next two Auckland concerts are to go ahead - but one is changing its date. 

Last night, the distraught performer, 72, was forced to call off his first Auckland concert midway through the performance at Mt Smart due to walking pneumonia and losing his voice.

The superstar, who earlier needed medical assistance while on stage, broke down in tears and needed to be assisted from the stage after attempting to launch into Daniel.

A statement released through a publicist this morning said: "Elton John was disappointed and deeply upset at having to end his Auckland concert early last night.

"He is resting today, and doctors are confident he will recover.

"At this stage, all remaining shows will go ahead as planned."

However, he has delayed his Tuesday show to Wednesday night. In a statement, promoters said that doctors have revised him to have an extra day of recovery, and that John is looking forwards to seeing fans on Wednesday and Thursday nights.

All tickets remain valid for Wednesday's show.

His Thursday show is currently still scheduled. He earlier played two concerts at Mission Estate Winery in Napier - jetting back for the Oscars in Los Angeles in between.

Last night, Daniel was number 16 in a 25-strong playlist. Herald concert reviewer Karl Puschmann said John's voice remained powerful during his early songs - until he spoke.

• Elton John forced to leave stage at Auckland concert

John reached out to fans on Instagram and Facebook an hour after the show was called off.

"I want to thank everyone who attended tonight's gig in Auckland. I was diagnosed with walking pneumonia earlier today, but I was determined to give you the best show humanly possible. I played and sang my heart out, until my voice could sing no more.

"I'm disappointed, deeply upset and sorry. I gave it all I had. Thank-you so much for your extraordinary support and all the love you showed me during tonight's performance. I am eternally grateful."

He signed the message off saying "Love, Elton xx".

John told the crowd early in the concert he had been diagnosed with "walking pneumonia" on Sunday morning. His voice was "shot", he said, but he was determined to lay on a great show.

The concert was paused for almost five minutes straight after John completed Someone Saved My Life Tonight about 8.40pm.

John remained on his piano stool as assistants and medical staff tended to him. His blood pressure was taken as the assistants spoke to him.

There were no announcements and John remained on stage. After several minutes and without speaking, John continued the concert with the song Levon.

The large screens flanking the stage had briefly gone dark but within minutes the concert resumed - to wild cheers from the crowd at Mt Smart Stadium.

He struggled to perform Candle in the Wind and told the audience he did not know how long he could continue as he "had nothing left". He left the stage just after 9pm and the stage, screens and stadium were left in darkness.

However he managed to return to the stage about eight minutes later in a new costume.

But several songs later, as he started Daniel, it was clear he had no voice. The show was over.

Walking pneumonia is an infection caused by bacteria that primarily affects an individual's lower and upper respiratory tract.

The condition is not as severe as the other forms of pneumonia and in most cases hospitalisation and bed rest are not required for recovery. It goes unnoticed and feels similar to the common cold for most individuals.