Discussions are being held to decide whether King Tuheitia's commitments at the end of the year will be passed onto someone else.
The Maori King has been in hospital since Sunday night due to "diabetes-related ailments", King spokesman Tukoroirangi Morgan said.
Initial reports suggested he had suffered a heart attack, however Mr Morgan told reporters gathered at Te Manukanuka o Hoturua Marae in Auckland that this was not the case.
"It can be confirmed that he did not suffer a heart attack," he said.
Mr Morgan said discussions were being held as to who would represent the King in his official duties if he was too unwell.
"The King has been overwhelmed with the outpouring of aroha and support," Mr Morgan said.
He is expected to be in hospital for at least a week for specialists to run a series of tests.
Mr Morgan said the King had been speaking with advisers but would not be receiving visitors at the hospital.
"He intends to return to official duties as soon as he is able," Mr Morgan said.
Mr Morgan said numerous leaders and ambassadors had extended their well-wishes to the King, for which he was grateful.
In one of his rare speaking appearances, a visibly-frail looking King Tuheitia last week addressed his health issues at his koroneihana (coronation) celebrations held at Turangawaewae marae in Ngaruwahia.
"You are well aware of my personal fight with diabetes and cancer and I am pleased to report that these are being kept under control," he said at the time.
The Herald understands he underwent a gastric bypass last year after his doctors recommended he undertake the procedure.
It's understood that the King's family have maintained their vigil at his bedside.
Both they and the Kingitanga have asked for privacy.