Prime Minister John Key says it will be business as usual with Australia, despite a change of leadership across the Tasman.
Julia Gillard has been sworn in as Australia's first female Prime Minister after ousting Kevin Rudd on Thursday.
Mr Key was the overseas leader to congratulate Ms Gillard. He spoke to her briefly, about an hour after the announcement by the Labor Party in Canberra.
He says that's a reflection of the very close and enduring relationship between New Zealand and Australia.
He also paid tribute to Mr Rudd, but says he now looks forward to working with Ms Gillard, in the interests of both countries.
Labour Party leader Phil Goff says the action against Mr Rudd by his colleagues was clearly driven by the polls and was based on pragmatism.
Both Mr Key and Mr Goff say it's a salutory reminder to see a politician plummet from a position of great popularity, so quickly.
Mr Rudd was due to visit New Zealand next week, but that is now cancelled.
Comparison to Helen Clark
A political academic at Auckland University says Ms Gillard possesses the same qualities that made Helen Clark popular enough to lead New Zealand for almost a decade.
Jennifer Curtin says Ms Gillard and Miss Clark are hard workers and good speakers and have similar political allies and portfolios.