The King is currently undergoing treatment for an undisclosed type of cancer PEOPLE can confirm that King Charles wrote a personal note to Joe Biden following the former president’s cancer diagnosis.

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.

Multiple reports confirm that King Charles has reached out to former President Joe Biden after he announced his cancer diagnosis. The Monarch, who has also been diagnosed with cancer, extended his support after Biden did the same a year ago.