Following a meeting with his estranged son Prince Harry, King Charles embarked on a journey to Sandringham on Tuesday.
Royal author Robert Hardman raises concerns about potential risks if King Charles continues with public duties during his cancer treatment.
Buckingham Palace confirmed on Monday evening that the King has been diagnosed with a form of cancer, prompting him to postpone his official engagements.
This announcement follows the King's recent hospitalization for a benign enlarged prostate, where he underwent corrective treatment.
Queen Camilla accompanied him as he departed The London Clinic last week, reassuring concerned observers that the King is "fine" and eager to resume his duties.
After a brief meeting with Prince Harry at Clarence House, King Charles and Queen Camilla headed to Sandringham. Prince Harry, who flew from Los Angeles to London overnight, spent a maximum of 45 minutes with his father before a helicopter departed from Buckingham Palace.
Robert Hardman, speaking to GBN America, highlighted the necessity for the King to withdraw from public engagements during his cancer treatment.
While the specific type of cancer remains undisclosed, Hardman emphasized the importance of avoiding large crowds and potential infections as the King undergoes treatment.
Despite scaling back public appearances, King Charles intends to continue with administrative tasks while Prince William and Queen Camilla assume a larger share of his duties.
Prince William will preside over the King's engagements, including leading investitures at Windsor Castle, in light of his father's health circumstances.