New Zealand’s Prime Minister announces sudden resignation

New Zealand’s Prime Minister John Key has unexpectedly announced his resignation, saying that he never saw himself as “a career politician”.

Addressing a news conference, Key said that it was the right time to quit politics.

Key, who had been widely expected to contest his fourth general election next year, said he wanted to ensure he did not make the mistake of some other world leaders by clinging onto power - and instead wanted to leave while he was "on top" of his game.

"Simply put, it has, for me, been the most remarkable, satisfying and exciting time of my life,” an emotional Key told reporters.

"But despite the amazing career I have had in politics, I have never seen myself as a career politician. I have certainly never wanted my success in politics to be measured by how long I spent in parliament."

Key, who recently marked his tenth year as leader of the centre-right National Party, said the role came with costs.

"For my wife Bronagh, there have been many nights and weekends spent alone, many occasions that were important to her that I simply could not attend," he said. "My daughter Stephie and my son Max have transitioned from teenagers to young adults while coping with an extraordinary level of intrusion and pressure because of their father's job."

He added: "It would be easy to say I have made this decision solely to rediscover the personal and family life I once had, and that is a factor, but it is one among many."