New Zealand Prime Minister Jacinda Ardern, who won global praise for her leadership style during the coronavirus pandemic, announced her resignation Thursday ahead of national elections later this year.

"I have given my absolute all to being Prime Minister but it has also taken a lot out of me," Ardern, 42, said in a statement. "You cannot and should not do the job unless you have a full tank, plus a bit in reserve for those unplanned and unexpected challenges that inevitably come along."

Lawmakers representing her ruling center-left Labour Party will vote Sunday on a new leader, who will lead the party to a national election Oct. 14.

The news came as such a surprise that Ardern had to dismiss suggestions she was trying to get ahead of a scandal by resigning, or was stepping down because her party has been trailing the main conservative opposition in recent voter polls.

"I'm not leaving because I believe we can't win the election, but because I believe Labour can and will win it. We need a fresh set of shoulders for the challenges of both this year and the next three," she said.

Ardern told reporters that she had discussed the decision with only a few people, and hadn't even told her 4-year-old daughter ahead of time.

"Four-year-olds are chatty," Ardern said. "I couldn't take the risk."

Ardern became New Zealand's youngest leader in more than 150 years when she was elected to office in 2017. Her win was viewed around the world as an antidote to the populist politics of the time, and global interest grew further when, in 2018, she became the second world leader in modern times to have a baby in office (Pakistan's Benazir Bhutto was the first). Ardern later took her 3-month-old daughter to the United Nations General Assembly in New York.

The young, center-left leader won praise for her calm stewardship of the Pacific nation through a number of major events, including the coronavirus pandemic, a volcanic eruption and a terrorist attack. In 2020, the Atlantic magazine described her as possibly the "most effective leader on the planet."

More recently however, local sentiment toward her government has soured as the small island nation emerges from a long period of pandemic isolation.

New Zealand is grappling with many of the pressures seen elsewhere: inflation, rising interest rates and housing affordability issues. It is also facing localized problems, such as a string of raids on jewelry stores and corner-store robberies - at least one of them deadly - that have led to perceptions among some voters that her administration is soft on crime.

Last month, Ardern suffered a rare lapse in composure in Parliament and was caught on a hot mic referring to a rival lawmaker using a pejorative word. (An official transcript of the remarks, in which Ardern compared him to a part of the male anatomy, was signed by Ardern and the lawmaker in question and later auctioned for charity.)

"I am human," she told reporters Thursday at a Labour Party caucus retreat in the coastal city of Napier. "We give as much as we can for as long as we can and then it's time. And for me, it's time."