LONDON, March 11, 2024 (BSS/AFP) - King Charles III said on Monday that he would continue to serve "to the best of my ability" after his cancer diagnosis, saying he had been "deeply touched" by people's wishes for his health.

The 75-year-old monarch, who became king in September 2022 after the death of his mother Elizabeth II, was admitted for surgery for a benign prostate condition in January but was subsequently diagnosed with an unrelated cancer.

He has postponed all public-facing duties while he undergoes treatment, but is continuing with behind-the-scenes work and has been holding some in-person meetings.

"In recent weeks, I have been most deeply touched by your wonderfully kind and thoughtful good wishes for my health," he said in a pre-recorded speech to mark the 75th anniversary of the Commonwealth.

"In return, can only continue to serve you, to the best of my ability, throughout the Commonwealth."

Charles's wife, Queen Camilla, 76, and son Prince William, 41, have taken on most of the royal family's duties in his absence.

William's wife, Princess Kate, 42, has also been absent from public life since undergoing abdominal surgery in January.

In his speech, Charles praised the diversity of Commonwealth and urged member nations to work together to overcome climate and economic challenges facing the world.

"Whilst we may not all have a shared history, we have common ambitions for a better future -- working together to build resilience and respond to global challenges," the monarch said in a speech recorded at Windsor Castle in February.

"Our diversity means that these challenges affect us all differently and that we experience their impacts in different ways," he said.

The Commonwealth, established in 1949, is home to one-third of the world's population, with the majority of the 56 member states being former British colonies in Africa, the Americas and Asia.