The head of prisons in the US state of Tennessee is set to resign after the failed execution of death row inmate Christa Pike on Wednesday.

Governor Bill Lee announced the change on Saturday, according to the BBC's US partner CBS News.

Tennessee Department of Correction Commissioner Frank Strada said in a statement to CBS that his stepping down is "in the best interests" of the state, and called the ongoing investigation into the incident "entirely appropriate and necessary".

Pike, who was sentenced to death in 1996 for the murder of Colleen Slemmer, survived two lethal injections and is now in critical condition at a Tennessee hospital as her lawyers seek to commute her sentence.