In a statement from Buckingham Palace, the king said he was “so proud of Catherine for her courage in speaking as she did,” according to People and The Guardian.
The statement also said King Charles, who received treatment in the same hospital as the Princess of Wales, has “remained in the closest contact with his beloved daughter-in-law throughout the past weeks.”
The statement said the king and queen “will continue to offer their love and support to the whole family through this difficult time.”
Prince Harry and Duchess Meghan also spoke out about Princess Kate’s cancer diagnosis and sent their well wishes.
More: Prince Harry, Duchess Meghan speak out on Princess Kate’s cancer diagnosis
March 22: Princess Kate reveals she has cancer in video, asks for privacy
After spending several months out of the public eye, Kensington Palace shared a video of the princess, in which she revealed she had been diagnosed with cancer.
“I wanted to take this opportunity to say thank you personally for all the wonderful messages of support and for your understanding whilst I’ve been recovering from surgery. It has been an incredibly tough couple of months for our entire family, but I’ve had a fantastic medical team who’ve taken great care of me for which I am so grateful,” she said.
“In January, I underwent major abdominal surgery in London and at the time it was thought that my condition was non-cancerous. The surgery was successful, however, tests after the operation found cancer had been present. My medical team therefore advised that I should undergo a course of preventive chemotherapy and I am now in the early stages of that treatment,” she added.