The Northern Territory government has backed an eight-week extension of the juvenile justice and child protection royal commission.
The federal government on Wednesday announced it has agreed to a second extension for the inquiry, pushing the final report out until September 30.
"I support the request for the additional time for writing," NT Chief Minister Michael Gunner told reporters in Alice Springs.
"What the royal commission has made clear is they've done a significant body of work and they want a greater period of time to be able to draft up that work into a report and into recommendations."
Mr Gunner has previously indicated he wanted to keep the original deadline so he can get on with his reform agenda.
"(But) we've done, parallel to the royal commission, a series of fixes to the youth justice system in the Territory, because clearly it was broken," he said.
"We are in a live situation. While the royal commission is investigating us, there are still children in our care and we have a responsibility to Territorians to make them as safe as possible.
"That means doing everything we can to prevent crime before it occurs."
The Labor government says the inquiry's interim report vindicated its $18 million overhaul to boost diversion workers and training for prison guards.
Attorney-General George Brandis said he had discussed the extension with the prime minister on Tuesday and granted it, following a request from co-commissioners Mick Gooda and Margaret White.
In December the inquiry was granted a four-month extension, at which time both the NT and commonwealth governments insisted no further delays would be allowed.
The cost of the inquiry, which is being jointly funded by the two governments, has already blown out by $4 million to $54 million.
Neither government allocated any money in their 2017 budgets to implement the inquiry's recommendations, which were originally due at the end of March and were rescheduled for August 1.
The commission was called after footage of boys being tear gassed at Darwin's notorious Don Dale Youth Detention Centre was aired on national television last year.
