Ailing U.S. broadcaster Casey Kasem's daughter Kerri has revealed her decision to withhold medication, food and fluids from her dying dad was one of the hardest decisions she and her siblings have ever had to make.

A judge in Los Angeles granted Kerri's request on Wednesday (11Jun14) after initially ruling that Kasem, 82, should not be denied vital life-saving drugs and liquid as he battled sepsis, dementia and Parkinson's disease.

And Kerri took to her Facebook page on Thursday (12Jun14) to explain herself, writing, "Transitioning our father's treatment to comfort-oriented care was one of the hardest decisions we've ever had to make.

"For people who do not understand the natural dying process: Giving food and water to a dying body creates pain and further suffering. The body does not want or require food or water anymore in the dying process. My father can no longer digest foods and fluids fill his lungs up and will suffocate him."

But she assures fans her father is on pain medication as the family prepares for his death in a Washington hospital.

He is surrounded by family and close friends, and Kerri is hoping that her stepmother Jean and her daughter Liberty will join them for her father's final days.

Kerri and Jean have been feuding for months after Kasem's daughter accused her stepmother of refusing to let her and her siblings visit their dad.

Jean stormed out of court on Wednesday after the judge ruled in favour of Kerri Kasem's request and later told reporters, "It's wrong, the courts are wrong," adding that everyone involved "has blood on their hands".