Papua New Guinea's Prime Minister, Peter O'Neill is expected to arrive in New Zealand for the Pacific Islands Forum leaders meeting on Wednesday afternoon.
Both Mr O'Neill and the former Prime Minister, Sir Michael Somare, were due to appear in Parliament today.
New Zealand's foreign minister, Murray McCully, says he understands Mr O'Neill will arrive in Auckland tomorrow.
"It was never intended that be here any early than that. I understand that Sir Michael is now back in PNG as of Sunday, but I am not sure that his state of health will see him making him making too many lengthy visits too far afield at the moment. But we wish him well for the rest of his recuperation."
Murray McCully says he believes it will be very difficult for the Vanuatu Prime Minister, and outgoing Forum chair of the Forum, Sato Kilman, to attend.
Last year, the then outgoing chair, Julia Gillard of Australia, also missed the Forum.