King Charles emotionally reacts to heartbreaking announcement from US

King Charles III got emotional after receiving sad news from the US, reacting to the devastating announcement with a message of support.

Prince Harry's dad wrote a heartfelt letter to express his support to former US president Joe Biden following his diagnosis of an aggressive form of prostate cancer.

The 76-year-old King, who's currently undergoing treatment for an undisclosed cancer himself, conveyed his best wishes to the politician during his difficult time.

Royal commentator Rebecca English confirmed the news on her official social media account, claiming: "King Charles is writing privately to Joe Biden following the news of his cancer diagnosis."

It comes after Biden's office announced on Sunday: "Last week, President Joe Biden was seen for a new finding of a prostate nodule after experiencing increasing urinary symptoms.

"On Friday, he was diagnosed with prostate cancer, characterised by a Gleason score of 9 (Grade Group 5) with metastasis to the bone. While this represents a more aggressive form of the disease, the cancer appears to be hormone-sensitive which allows for effective management."

Biden left office in January as the oldest serving US president in history and questions about his health dogged his first term, leading him to end his run for re-election late in his campaign.