The Prime Minister has apologised to both the mother and her children who spent almost four years isolated in the bush with their father, Tom Phillips.

A report by Honourable Justice Simon Moore KC was made public on Tuesday, more than a year after Phillips died in a police shootout in rural Waikato.

It found the concerns of maternal whānau of the children were "minimised or overlooked by agencies for significant periods" and a more collaborative approach from Oranga Tamariki (OT) and NZ Police "could have prevented the children's disappearance and brought them back sooner".

Prime Minister Christopher Luxon did not attend the press conference at Parliament alongside minister in charge of the inquiry Louise Upston, Police Commissioner Richard Chambers, and OT chief executive Amanda Malu.

On Wednesday afternoon on his way into Question Time he told reporters the inquiry had made clear some of the actions by the agencies involved hadn't been handled well.

"So there were missed opportunities, and we're sorry about that, and we're sorry about the impact that it's had on those children."

Luxon said he had read the 200-page report and it was clear there were opportunities "for us to improve".

When it was put to him that the mother of the three children had spent years warning agencies about Phillips and hadn't been listened to, Luxon said for that he was sorry.

"I'm genuinely sorry about that.

"I'm genuinely also sorry about the children that were let down through this process that spent four years in the bush."

This week Luxon spoke on the phone with the police officer who was critically wounded in the shootout with Phillips, The officer is still undergoing a long recovery.

Asked why he hadn't met the mother of the children involved, Luxon said "it's entirely appropriate that the operational heads of the agencies do so".

He said both Chambers and Malu had made it clear they were "comfortable sitting down with the mother and meeting with her" and that was the best way to deal with that.

Labour leader Chris Hipkins told reporters on Wednesday he still hadn't read the full report but the "lowlights" he had seen were "very sobering".

On whether Luxon should have fronted the apology and press conference on Tuesday, Hipkins said he would have if he was prime minister.

"What he does is up to him... he's failed to show leadership for the last three years.

"I'm not sure why New Zealanders would expect that from him now," he said.