"Given unhealthy rumours that I was headed to Cuba for the funeral, I want to state clearly that I have never returned to the island, and I don't plan to do so," Castro told El Nuevo Herald yesterday.
"I'm not rejoicing in any human being's death, nor would I do that with someone who shares my family names," she went on. "As Fidel's sister, I am going through the loss of a human being who shared my blood."
Fidel and Cuban President Raul Castro were among their parents' seven offspring. Juanita, born in 1933, was the only one to publicly oppose the Communist regime her brother led for over five decades.
She has been living in Miami since 1964, and said she cooperated with a CIA plot to oust Fidel.