Prime Minister Justin Trudeau wished King Charles a speedy recovery after Buckingham Palace revealed that the King has been diagnosed with cancer.

Trudeau said upon hearing the news that he is thinking of the King, just like countless others across Canada and around the world.

The palace did not reveal additional details, except to say that the cancer is unrelated to the King's recent treatment for a benign prostate condition.

The palace noted that King Charles has already begun treatment and will postpone some of his public duties, although he will continue to handle routine paperwork and state affairs.

The diagnosis news comes as the wife of his son Kate, Princess of Wales, recovers from abdominal surgery that led to her being hospitalized for about two weeks.

The palace says the King is being treated as an outpatient.

Trudeau said on social media: "I, like Canadians across the country and people around the world, am thinking of His Majesty King Charles III as he undergoes treatment for cancer."

"We send him our best wishes – and hope for a speedy and complete recovery."

In a special post, Ralph Goodale, Canada's High Commissioner to the United Kingdom, described the news as "concerning" and wished the King a "speedy and full recovery."