WELLINGTON, New Zealand (AP) — New Zealand's popular Prime Minister John Key stunned the nation on Monday when he announced he was resigning after eight years as leader.

Key had been widely expected to contest his fourth general election next year. But he said he wanted to ensure he didn't make the mistake that some other world leaders have done, and instead wanted to leave while he was on top of his game.

Speaking in a shaking voice, Key said he had made personal sacrifices for the job and the role had taken a toll on his family.

Key said his National Party caucus would meet on Dec. 12 to decide on a new party leader and prime minister.

Key said he would back his deputy Bill English for the role.