London — Britain's King Charles has issued his first statement since the public announcement of his cancer diagnosis.  

In a statement issued by the British royal family Saturday, King Charles said he would like "to express my most heartfelt thanks for the many messages of support and good wishes I have received in recent days."

"As all those who have been affected by cancer will know, such kind thoughts are the greatest comfort and encouragement," he added. 

Charles was diagnosed with cancer while he was undergoing treatment for an enlarged prostate last month. Buckingham Palace said he would step back from his public duties during his treatments, but it has not said how long they will take.

CBS News Royal contributor Julian Payne said the king has generally enjoyed "very robust health," and Charles took a bold step by addressing his health problems, which may be due to a desire to encourage others to get themselves checked and make doctor's appointments. 

Palace officials said that Charles was undergoing "regular treatments," but did not specify what type of treatment the monarch was undergoing.

Prince Harry — who's had a fractured relationship with the royal family for years — flew from Los Angeles to London after his father's diagnosis was announced. He has since returned to California. 

His brother, William, the Prince of Wales, has also been supporting his wife, the Princess of Wales, as she recovers from abdominal surgery. He returned to public royal duties Wednesday and attended an investiture ceremony at Windsor Castle. He then headed to a gala dinner for London's Air Ambulance Charity where actor Tom Cruise was also in attendance.

"It's fair to say the past few weeks have had a rather medical focus, so I thought I'd come to an air ambulance function to get away from it all," joked the prince at the gala.

Prince William is next in line for the throne. 

— Haley Ott contributed to this report.

In:
• Queen Camilla
• King Charles
• Britain

Cara Tabachnick is a news editor and journalist at CBSNews.com. Cara began her career on the crime beat at Newsday. She has written for Marie Claire, The Washington Post and The Wall Street Journal. She reports on justice and human rights issues. Contact her at [email protected]