New Zealand's Health Minister David Clark has resigned, saying he had become a distraction to the government's response to the COVID-19 pandemic after a series of blunders.

Dr Clark was demoted in April when he revealed he had broken restrictions on movement, going mountain bike-riding and taking his family for a trip to the beach.

Last week, he appeared to lay blame for lapses in the quarantine system at the feet of director-general for health Ashley Bloomfield.