Jacinda Ardern has announced she will quit as New Zealand prime minister next month, saying she no longer has "enough in the tank" to lead. Ms Ardern choked up as she detailed how six "challenging" years in the job had taken a toll. She will step down as Labour Party leader no later than 7 February. There will be a vote in the coming days to determine her replacement. New Zealand will hold a general election on 14 October. Ms Ardern, 42, said she had taken time to consider her future over the summer break. "I had hoped that I...