As the monarch made his first remark, Prince William thanked the public for their good wishes in response to his father, King Charles III’s, shocking cancer diagnosis.
Charles sent a letter to Grenada to celebrate the Caribbean island’s 50th anniversary of independence.
While the message focused primarily on the nation and the king’s recollections of visiting, he did mention at the end that he was unable to celebrate in person.
“I can only say how sorry I am that I cannot be with you in person to mark this momentous milestone, and to enjoy a little Oil Down with you all!” the king wrote.
“My thoughts are with everyone across Grenada, Carriacou and Petit Martinique, and all those in Grenada.”
Meanwhile, William took center stage in royal public responsibilities as his brother, Prince Harry, was scheduled to return to the United States without speaking to him.
“I’d like to take this opportunity to say thank you … for the kind messages of support for Catherine and for my father, especially in recent days. It means a great deal to us all,” the Duke of Cambridge said at a gala dinner for London’s Air Ambulance Charity.
“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.”
The prince made his second formal public appearance on Wednesday (local time) after returning to work following his wife Kate’s anticipated stomach surgery on January 16.
The Princess of Wales spent two weeks in the hospital resting
Since then, Buckingham Palace confirmed on Monday that Charles, 75, had been diagnosed with a form of cancer.
With the king postponing public duties to undertake outpatient treatment and Kate not scheduled to resume engagements until after Easter, the onus will be on the remaining royals, particularly William and Queen Camilla, to be the monarchy’s public face.
William had already assumed significant state responsibilities near the end of Queen Elizabeth’s reign, according to royal chronicler Robert Hardman, when she was plagued by mobility problems.
“In that regard, it’s not that different but obviously there’s the burden of expectation,” Mr Hardman told Reuters.
“On many occasions, he will have to stand in, he’ll be sort of quasi head of state in much the same way that Prince Charles was when the queen was infirm.”
Since leaving royal duties nearly four years ago, Harry has scarcely spoken with many of the Windsors due to his criticism of the monarchy.
According to a royal insider, he has no intentions to see his elder brother William during his visit to Britain.
After only 24 hours in Britain, Harry returned to California without visiting his brother.
According to Prime Minister Rishi Sunak’s spokeswoman, the king would speak with him by phone on Wednesday.
Buckingham Palace has not revealed any information about the king’s ailment other than the fact that it is not prostate cancer, but has stated that he is “wholly positive” and hopes to return to public duty as soon as possible.