A large spike in incarcerated children and self-harm at the Northern Territory's Don Dale prison has sparked grave fears it could take a death for serious steps to be taken to address the issue.

Aboriginal Medical Services Alliance NT chief executive John Paterson, Danila Dilba chief executive Rob McPhee and Northern Territory Council of Social Service chief executive Deborah Di Natale issued a statement Wednesday morning urging the Territory Government to reduce youth incarceration.

The call was sparked after it was revealed acting children's commissioner Nicole Hucks had written to Territory Chief Minister Natasha Fyles to raise "grave concerns" about a 200-per cent increase in children in detention in two years and 400 per cent rise in cases of self-harm in one year at Don Dale.

Mr McPhee said the Territory government's "tough on crime" attitude solves nothing.

"Detention or locking kids up isn't the answer," he said.

"We know that putting a child in a facility like the old Berrimah adult jail is traumatising and likely to negatively impact on the wellbeing of that child and their future forever. This must stop."

The group said the government was breaching the UN Convention on the Rights of the Child.

It noted that five years ago the Royal Commission into the Protection and Detention of Children in the Northern Territory recommended a trauma-informed therapeutic model of youth detention and that children only go into custody as a last resort.

"But last year the NT Government ensured the opposite occurred, when it toughened the youth bail laws and ensured that children in the NT are being unnecessarily imprisoned at rates higher than they have ever been," the statement said.

Ms Di Natale said she visited Don Dale last week to see the conditions for herself.

"I cannot reconcile how in a wealthy country we can keep children in such dehumanising conditions devoid of a therapeutic approach," she said.

"The acting children's commissioner has raised critical issues and we cannot wait until late 2023 for the new detention facility to open, we must urgently act."

Mr Paterson said it was unacceptable that girls in detention had no privacy when showering and are not provided with enough sanitary items.

A Northern Territory government spokesperson said the government was closing Don Dale and building a new fit-for-purpose youth detention facility.

"The government is introducing reforms that focus on community safety while delivering the most progressive youth justice infrastructure and system in Australia, including early intervention and diversion programs," they said.

"The youth justice system we have today is a far cry from that which this government inherited. It includes a therapeutic model of care developed with extensive stakeholder input, which is now being rolled-out across the system."

The Territory justice department said damaged and removed shower curtains were promptly replaced, and temporary screens were installed so female detainees could shower in private.

The department said detainees had access to sanitary products at their discretion.

• 13 YARN - 13 92 76