A US woman has pleaded guilty to killing two of her children and storing their bodies in a home freezer, telling a judge she has no remorse for beating and suffocating them.

Mitchelle Blair, 36, of Detroit, Michigan, has never challenged allegations that she killed her 13-year-old daughter and nine-year-old son.

She pleaded guilty to first-degree murder without any deal with prosecutors — an extraordinary move — and said she would have accepted the death penalty if the state of Michigan had it.

Blair was arrested in March, after deputies carrying out an eviction at her apartment found the bodies of her children in a deep freezer.

She said she attacked the children months apart in 2012 and 2013.

Blair said she intended to kill her daughter, Stoni Blair, but didn’t know the abuse of her son, Stephen Berry, would be fatal.

Blair alleged the children had sexually abused a sibling, though she said she didn’t witness the alleged assaults and didn’t get police involved because she feared she would lose her other two children.

“I don’t regret none of this,” Blair told Judge Dana Hathaway during the hearing. “I don’t feel no remorse for the death of those demons.”

Mental health experts had found Blair competent to face charges. She faces life in prison with no chance for parole.

The judge asked a series of questions about what happened. Blair said she repeatedly beat Stoni and Stephen, and poured scalding water on them.

She said she made Stephen drink window cleaner. Asked if she had ever called police about the alleged sexual assaults, Blair said she called police with a “hypothetical” situation, seeking to know if other children in the home would be removed if she reported the assaults.

In a separate case, authorities are seeking to end Blair’s parental rights to her other children and those of their fathers, saying the men don’t take care of them.