British Prime Minister Rishi Sunak said Tuesday that he was “shocked and sad” to learn that King Charles III has cancer, but is relieved that the illness was caught early.

Buckingham Palace announced Monday evening that the king has begun outpatient treatment for an undisclosed form of cancer. It was found during his recent treatment for an enlarged prostate but is not connected to that condition, the palace said.

“Thankfully, this has been caught early,” Sunak told BBC radio, adding that as prime minister he would “continue to communicate with him as normal.”

“He’ll just be in our thoughts and our prayers. Many families around the country listening to this will have been touched by the same thing and they know what it means to everyone,” Sunak said. “So we’ll just be willing him on and hopefully we get through this as quickly as possible.”