LONDON - Britain's King Charles was shown on Friday reading and chuckling at some of the thousands of cards sent to him by well wishers since it was announced he was receiving treatment for cancer.

Buckingham Palace disclosed earlier this month that Charles, 75, had been diagnosed with a unspecified form of cancer, less than 18 months into his reign.

Charles told Prime Minister Rishi Sunak earlier this week he had been reduced to tears by some of the messages of good will he had received, and the palace released footage on social media of him reading some of the cards.

Some of the more than 7,000 letters and cards sent to the monarch detailed the writers' own experiences with cancer, while others offered prayers and wishes for a speedy recovery.

"Chin up, chest out, remain positive and don’t let it get you down," one letter said, while the king was also shown chuckling at a comedy card which pictured a dog wearing a protective cone on its head.

While Charles is carrying on with his official state work, his public engagements have been postponed while he undergoes treatment.

(Reporting by Michael Holden; Editing by Cynthia Osterman)