The prime minister says she agrees with David Clark's decision to resign as minister of health
Clark formally resigned as minister after controversies over his handling of the Covid-19 response.
He will be replaced by Minister of Education Chris Hipkins until the election, Ardern said in a statement. "Post-election I intend to reassess who is best placed to take the health portfolio forward."
Ardern said she received Clark's resignation yesterday.
She said late last week she had open discussions with him in person about the importance of the government's Covid-19 response.
"What has become clear to the minister, and an assessment I agree with, that unfortunately his role was continuing to be a distraction to our response, and that just wasn't something we could have continue.
"I want to thank him for his service, he delivered a lot in his three years.
"We cannot afford any diversions from our objectives."
Clark will not be reappointed next term, she said.
She said he had thought through what had happened in the past weeks and this was his view that he needed to go.
"Whilst Minister Clark made this decision, it is one I agree with."
Watch the PM's press conference here:
Earlier, Ardern said in a statement it was essential the public had confidence in the health leadership.
"David has come to the conclusion his presence in the role is creating an unhelpful distraction from the government's ongoing response to Covid-19 and wider health reforms.
"It's essential our health leadership has the confidence of the New Zealand public. As David has said to me the needs of the team must come before him as an individual.
"Our response to Covid is on a stable footing and I have full confidence that Minister Hipkins will oversee the portfolio with the thoroughness and diligence he brings to his other areas of responsibility."
Hipkins said he will be working through the Covid matters with the health teams, as well as the Heather Simpson review.
He said he had a good working relationship with Bloomfield and regarded him as an exemplary public servant.
Asked about his experience in health, he said: "I have experience working in a big operational portfolio that has a lot of complexity, I had no experience working in the education portfolio when I became minister of education.
"I will be giving it my all up until the election."
Clark first came under fire during the pandemic when it was revealed he took a trip to a beach with his family in the first week of level 4 lockdown. Although he offered to resign at the time, the prime minister reprimanded and demoted him but did not sack him.
The Dunedin-based MP admitted to a second breach, after driving to a mountain biking track during lockdown.
Ardern said under normal circumstances she would have sacked him.
Asked about why she didn't sack him at the time she said: "We couldn't afford to lose one of our key players at the time."
"Covid-19 will be with us for a long time, our response will need to continue for a long time to come."
Ardern would not be drawn on whether specific incidents had led to his resignation now.
"We need as a country, as a government, as a Cabinet, to be totally focused on our Covid response. Anything regardless of origin - anything that acts as an unnecessary distraction to that, we just simply couldn't afford.
"That doesn't take away from the wider work that he has done as a minister, mental health in particular will be a legacy of Dr David Clark."
Recently, National Party leader Todd Muller had called for Ardern to fire Clark over the handling of quarantine exemptions after two women were given quarantine exemptions and later tested positive for Covid-19.
Clark had also faced a backlash after repeatedly saying Director-General of Health Dr Ashley Bloomfield was the person responsible for failures at the border, and only taking responsibility himself as minister after several days.