New Zealand's political parties have been stunned by Prime Minister John Key's resignation today, but have paid tribute to his eight years in power.
Mr Key made the announcement early this afternoon, saying it felt like the "right time to go" ahead of next year's general election.
He will step down as Prime Minister and National Party leader next week, and a special meeting will be held on 12 December to select the party's new leader.
Labour leader Andrew Little said Mr Key had served New Zealand "generously and with dedication".
"I wish him and his family the best for the future."
Mr Little said Mr Key had been a very popular prime minister, and it was a brutal job on people and their families.
"We may be in a very political environment here, but when the nation's prime minister steps down, there is a time to take to reflect on that. I don't want to get too political about this, but I think someone like John Key, who has served in the way he has, let's recognise that, acknowledge it and thank him for his public service."
Mr Little said Mr Key had lead the country through very difficult periods, including earthquakes and the financial crisis.
United Future leader Peter Dunne told RNZ he was stunned.
"I got a call from the Prime Minister about 12.20 this afternoon to inform me and he gave his reasons, as I understand it family, time to move on, time to give a new leader a good chance with the run-in to the election next year etc.
"I admire him for having the courage to make that call, it would have been very easy if his mind was somewhere to have simply carried on for the sake of the party. It's a huge decision and it's one I think that no one in their wildest dreams would have imagined happening.
"The test will be just who the new leader is, how that beds down, and what the reaction of New Zealand is. I think most New Zealanders will take a day or two to absorb this, and then they will make a judgement based on what they see the likely new line-up looking like."
Mr Dunne said it made politics in 2017 a "whole new ball game".
ACT leader David Seymour has also put out a statement, congratulating Mr Key on the past eight years and the "noble way he has bowed out".
NZ First leader Winston Peters told RNZ that it was always clear the Prime Minister "would cut and run before the next election".
Mr Peters said Mr Key was resigning because his popularity rating was falling. He also said the economy was not as strong as the government claimed, and people would start to realise it.
Green Party co-leader James Shaw said the party thanked Mr Key for his eight years of service as the country's leader.
"No matter your political allegiance, you have to respect someone who chooses to make the personal sacrifices required to be our country's prime minister," he said.
"Being the leader of a major political party, and indeed the country, is not an easy job."
The Māori Party said it would always be grateful to Mr Key for "making a space at the table of his government for a kaupapa Māori Party".
"It has been under the leadership of John Key that the Māori Party has been able to secure gains for Māori and advance kaupapa Māori over the past eight years," said Māori Party co-leader Te Ururoa Flavell.
"We may not have agreed on everything but we've always maintained a respectful relationship with the Prime Minister and he with us," said Mr Flavell.
"We've had some tough talks on many issues but at the end of the day, respect for each other prevailed and that's why he has always seen us as a party that governments can work with," said Māori Party co-leader Marama Fox.
"We're all about whānau in the Māori Party, so we understand and support Mr Key's call to return to his family and be with them more."
Former prime minister Jim Bolger said he had no sense Mr Key would step down, but it was a decision every leader had to face at some time.
Mr Bolger, who led the National Party for 12 years and the country for seven, said Mr Key could leave with his head held high.
Mr Bolger said being leader for a long time took its toll.