Sir Paul Holmes answered the phone with a hoarse voice and acknowledged his health circumstances had changed.
His investiture ceremony has been brought forward to next Wednesday, a rare move that has caused concern.
"It's not urgent, but it acknowledges a changing of circumstances which is happening - but it's not an emergency situation."
The veteran broadcaster, journalist and author was made a knight in the New Year's honours for his services to broadcasting and the community. He worked in broadcasting for more than 30 years, becoming one of New Zealand's most well-known personalities and championing several causes, including the Paralympics and the fight against methamphetamine.
The Governor-General, Lieutenant-General Sir Jerry Mateparae, will travel to Hawkes Bay for the ceremony.