New Zealand's High Commissioner to the Cook Islands, Tessa Temata, died in Palmerston North at the weekend.
Ms Temata, 52, had recently returned to New Zealand for medical treatment.
Deputy Prime Minister and foreign minister Winston Peters says the goverment has extended its deepest sympathies to her family, friends and colleagues.
Ms Temata was New Zealand's first High Commissioner of Cook Islands descent to serve there, and also the first female New Zealand High Commissioner of Pacific ancestry to be posted to the Pacific.
Ms Temata's family hails from Samoa and the Cook Islands.
"A respected diplomat with over 25 years' experience in trade, development and legal matters, Tessa made a particularly strong contribution to deepening New Zealand relationships with Pacific Island countries," Mr Peters said.
Since joining the Foreign Ministry in 1992, she had postings in Indonesia, Papua New Guinea, Kiribati, Niue and Cook Islands.
Mr Peters said this was a difficult time for Ms Temata's colleagues, particularly those at the High Commission in Rarotonga, who all knew her as courageous and inspirational.
"Ms Temata served her country with great distinction," he said.
"The Pacific is the part of the world where New Zealand can and does make the most difference. It is therefore to Ms Temata's great credit that she spent so much of her career serving right across the Pacific.
"She demonstrated how much of a difference expertise, warmth, hard work and cultural competence can make to New Zealand's Pacific diplomacy. She will be hugely missed," Mr Peters said.