Christopher Luxon says the video showing an MMA-style fight at an Oranga Tamariki youth justice residence is "heartbreaking" and "sickening".
Newshub exclusively revealed on Tuesday evening footage of the fight that occurred at Korowai Manaaki in south Auckland - the same facility where, just days ago, five teenagers escaped onto the roof, causing significant damage during a 40-hour standoff.
Police are investigating and four staff members at the facility have been stood down.
The video shows two young men unleashing on one another, egged on by fellow residents.
One of them is knocked down and called an expletive for not getting up. He fights on, is violently knocked down and can't get up.
National Party leader Luxon told AM on Wednesday the video is shocking and deeply concerning.
He told AM co-host Ryan Bridge New Zealand's most vulnerable kids have the right to feel safe in Aotearoa.
"Every child in New Zealand deserves to feel safe and particularly our most vulnerable and most troubled youth," Luxon said.
"They're in state care and the job of the minister is to keep them safe. So it's incredibly worrying, incredibly concerning and as you say, heartbreaking and sickening."
Oranga Tamariki has been in the headlines a lot recently. Five unruly teenagers spent over 40 hours on the roof of the Wiri youth justice facility before being given KFC and McDonald's to come down.
The weekend before that, five other teenagers also escaped and made it onto the roof at the Te Puna Wai o Tuhinapo youth justice facility near Christchurch. They caused significant damage and a staff member suffered a fractured wrist.
They also spent the night on the roof before also receiving fast food to end the stand-off.
Oranga Tamariki was also in the headlines when it was revealed two staff members were removed from the Government department residences after allegations of inappropriate and sexual behaviour surfaced.
National has been very vocal about crime in New Zealand since Luxon became leader of the party at the end of 2021.
If elected National would send young offenders aged 15-17, who commit at least two serious offences, to military camps.
When pressed by Bridge about how National's boot camp policy could potentially make these issues within Oranga Tamariki worse, Luxon defended it saying the current issue is with the staffing inside each facility.
"That's why Mike Bush with his leadership profile and his background has been brought in to look at all of this," he told AM.
"It's wonderful that Mike's in there and he's someone I really admire and I really support, but the point is, the minister and the management should know what's going on in these facilities."
Luxon wouldn't say if National would build more of these youth justice facilities.
"I don't know, I haven't thought that part through, but the key thing for me is making them work and they can work if you actually put the right mentors, the right leaders and get the right interventions in there," he said.
"We have other great community organisations that are doing incredible work, turning young people's lives around as well and we know we can do it. It's hard work, don't get me wrong, it's difficult work, but it's work that we've got to stay committed."
Watch the full video with Christopher Luxon in the video above.