New Zealand Prime Minister Jacinda Ardern announced on Thursday that she will resign next month.

“Jacinda Ardern says she will not be seeking re-election this year and her last day as prime minister is 7 February. The 2023 general election will take place on 14 October,” tweeted RNZ, New Zealand’s public broadcaster.

“For me it’s time. I just don’t have enough in the tank for another four years,” she said at a meeting of members of her Labour Party, according to media reports.

The surprise decision from Ardern comes after five and a half years of tenure leading New Zealand through the coronavirus pandemic. But she has seen a decline in popularity in recent polls.

Ardern said she knew what the prime minister’s job took and believed she “no longer had enough in the tank to do it justice” but there were colleagues who could.

She said her Government had achieved a lot and she was not standing down because she did not believe Labour could win the next election, but because she thought it could.

Speaking to the media, Ardern said there was no special “angle” or “real reason” why she wanted to resign, only that she was “human”.

“To Neve, mum is looking forward to being there when you start school next year. To Clarke, let’s finally get married.”

Ardern’s Labour Party will begin looking for a successor with a caucus vote on Saturday.

At only 37 years old at the time of her election to power in 2017, Ardern is one of the world’s youngest female state leaders.