Brazil's suspended president Dilma Rousseff admitted Tuesday she had made mistakes but said she had done nothing worthy of impeachment in an address just over a week before she goes on trial.

"I am innocent," she said in a statement to Brazilians.

Rousseff also reiterated her backing for a referendum on holding early elections and the need for electoral reform to carry out a "deep transformation" of a system that most Brazilians consider rotten.