The armed man shot by police just outside of Paeroa this morning got "very close" to officers with a machete and sickle.
Police revealed that officers had feared for their safety in the lead-up to shooting in Karangahake, north Waikato.
Police were called to the small community after reports that the 57-year-old man was threatening another person with a machete.
Police shot the man after he threatened them with the blade. He died at the scene.
When asked at a press conference how close the man who got to officers, Acting Assistant Commissioner Bruce Bird replied: "Very close."
"They were fearing for their lives and that's why they were using the firearm."
Mr Bird said he "absolutely" backed the officers decision to fire a shot at the man, who is yet to be named by police.
"Our officers are well trained, they have got to make judgment decisions and all the current facts that I have before me, they made the right decision."
Police have cordoned off a property in County Rd, Karangakahe, and are providing support to the man's family and the officers involved in the incident.
Police said the partner of the dead man and her two children - a 14-year-old girl and 17-year-old boy - lived at the property. Neither the partner nor the children were injured in the incident.
Mr Bird says the three officers involved were "attacked" but none were injured.
"It was a fast moving, dynamic scene but we need to reconstruct that to determine the facts."
The shot man was armed with a sickle and a machete when he went to attack the officers.
A "number" of other knives were also found at the scene.
Mr Bird says it wasn't the first time police had been called to the house. "We do know about other incidents that have occurred at the house for a variety of reasons."
That was why officers armed themselves before heading to the property, Mr Bird said.
Officers were armed with a taser but it could not be used. When asked why, Mr Bird says it was too early to say but that would form part of the IPCA investigation.
"Police officers had a taser available but they couldn't deploy the taser at the time and used a firearm."
He added: "The officers are going through a real emotional rollercoaster and we haven't yet been able to speak to them."
Hauraki District mayor John Tregidga said he was shocked by the fatal shooting.
"It's a huge shock and a surprise because Karangahake is a very close-knit community. It's a lovely little community," he said.
Neighbours told the Herald the shot man involved was well known in the community and to police.
He had lived at the property, which has a caravan outside, for several years. His partner is the woman listed as being the owner of the property.
A resident said they had been passing the area just as the first police officer arrived at the scene.
"There was just one policeman. I think he was stopping people from going down the driveway towards where the incident took place.
"Since then, there's been a heap of police and ambulance [and] fire trucks there.
Over the years, a number of equine events have been held at the property.
"They do some sort of horse thing there," the neighbour said.
"They do horse training. Sometimes I see some signs up directing people down there."
The man involved has been known to threaten neighbours and had put up several gates along the Hauraki Rail Trail, blocking access, neighbours said.
In his regular online blog police commissioner Mike Bush referenced the incident.
"Our investigations at the scene are continuing and we are ensuring that all staff involved are receiving all the support they need. Our thoughts are also with the family of the deceased at this tragic time."
Police Association president Greg O'Connor said the organisation was "fully supporting the officers involved in today's fatal shooting in Paeroa after a man attacked police with a machete".
"This is the situation every police officer dreads. It's a possibility police face every time they go on shift. Every officer goes to work hoping they will not be placed in a position where they are forced to use lethal force. However, if that situation arises, they deserve the support of the public they are sworn to protect," Mr O'Connor said.
"Inevitably, armchair critics will speculate and make judgments about what 'could' or 'should' have been done. But the officers involved were the people who were there facing the situation, who had the training, and who were faced with the responsibility of actually making a decision."
Mr O'Connor said the shooting would be subject to investigation by police, the Independent Police Conduct Authority and the coroner, which could take some time.
"But until they are complete, no one should criticise the judgment call that the officers involved were forced to make."
The 19-year-old disappeared without her wallet or mobile phone.