Britain's King Charles III has written a private letter to former President Joe Biden, Buckingham Palace said, following the latter's diagnosis of an aggressive form of prostate cancer, which has metastasized to his bones.

King Charles gave a rare update on his cancer journey during an engagement last week. The monarch spoke about his health during a visit to Bradford, England, while in conversation with florist Safeena Khan.

King Charles has written privately to Joe Biden after the former President’s office announced that he has been diagnosed with an aggressive form of prostate cancer. Buckingham Palace confirmed today that a message had been sent from the King although no further information about its content was released.