NEW YORK, May 31. /TASS/. Former US President Joe Biden jokingly said he could "beat the hell out" of the authors of the book "Original Sin: President Biden's Decline, Its Cover-Up, and His Disastrous Choice to Run Again," which discusses his rapid physical and mental deterioration in 2023.

"You can see that I’m mentally incompetent, I can’t walk — and I can beat the hell out of both of them [the authors]," he said ironically to reporters in Delaware.

Biden said that he was optimistic about his prostate cancer treatment. "Well, the prognosis is good. You know, we're working on everything. It's moving along. So, I feel good," he said, adding that he is taking the necessary medication.

On May 18, Biden's office announced that the 82-year-old former president had been diagnosed with an aggressive form of prostate cancer that had metastasized to his bones. US President Donald Trump expressed doubts that his predecessor's diagnosis had only now become known, hinting at a possible cover-up.