Governor-General Sir Jerry Mateparae is recovering in hospital after undergoing heart surgery.
Sir Jerry was scheduled for valve replacement surgery after a heart problem was picked up during a routine check in October, a statement from Government House said.
The statement said he would remain in hospital for the next days.
Administrator of the Government Dame Sian Elias would take over Sir Jerry's duties for two weeks.
Once Sir Jerry had been released from hospital, he would recuperate at Government House.
Some events on his diary during December had been cancelled to help him recover.
Sir Jerry's most recent public appearance was at a memorial service for Jonah Lomu in South Auckland on Saturday.