Jim McLay, New Zealand's representative at the United Nations in New York, will be replaced in May by career diplomat Gerard van Bohemen after Mr McLay's second term ends, Foreign Minister Murray McCully has announced.
By dint of the appointment, Mr van Bohemen will also represent New Zealand on the Security Council for the rest of 2015 and 2016.
Mr Van Bohemen is a deputy secretary at the Ministry of Foreign Affairs and Trade responsible for multilateral and legal affairs.
It is thought he would have been short-listed for the job of Secretary of Foreign Affairs to replace John Allen if he had wanted it, but was keen to return to New York.
He was deputy permanent representative when New Zealand was last on the Security Council in 1993-94.
Mr McLay, a former Deputy Prime Minister and former National leader, has been in New York for five and half years. He will become a special adviser to Mr McCully when he returns to New Zealand and will be New Zealand's representative to the Palestinian Authority.
"In this capacity he will serve as a Special Envoy for the Prime Minister at appropriate regional meetings and undertake a range of other duties which will utilise his network of contacts and special knowledge of UN matters."
Giving Mr McLay credentials to the Palestinian Authority deals with a diplomatic spat between New Zealand and Israel after Israel last year rejected New Zealand's nomination as Israeli ambassador, Jonathan Curr, on the grounds that he was also accredited to the Palestinian Authority.
By making Mr McLay ambassador, the Israeli's get their way but New Zealand has arguably made a more senior appointment to the Palestinian Authority.
Mr McCully said Mr McLay could take considerable credit for New Zealand's successful campaign for a non-permanent seat on the Security Council, which it won after a 10-year campaign, five of which were led in New York by Mr McLay.