Darlene MacDonald told the Winnipeg Free Press last week that she's concerned about the millions of dollars an inquiry into the 2005 death of five-year-old Phoenix Sinclair will cost.
She said the money would be better spent on improved resources for families and children.
The Assembly of Manitoba Chiefs, Manitoba Keewatinowi Okimakanak and Southern Chiefs Organizations said in a joint news release Wednesday that they are -- quote -- "greatly disappointed and concerned" with MacDonald's comments.
They say MacDonald's office has not sought standing at the inquiry, and say her job is to work and protect children in Manitoba, not for the interests of the government.
Liberal Leader Jon Gerrard has also called for MacDonald to resign.
The public inquiry, headed by retired judge Ted Hughes, is scheduled to begin hearing testimony in September.
Phoenix spent most of her short life in foster care before being handed back to her mother. She died after being tortured, confined and assaulted inside the family's home on the Fisher River reserve.
It took more than nine months for officials to realize the toddler was missing despite the fact she had been in Child and Family Services care and had only recently returned to her family
Her mother, Samantha Kematch, and Kematch's boyfriend, Karl McKay, were convicted of first-degree murder and are serving life sentences.