King Charles III on Tuesday makes his first official public appearance since being diagnosed with cancer, after doctors said they were “very encouraged” by the progress of his treatment.

The British head of state and his wife, Queen Camilla, were expected to tour a cancer treatment facility to meet medical specialists and patients.

Charles, 75, suspended public-facing duties in February after cancer was found while he was being treated for an enlarged prostate the previous month.

The exact nature of his cancer has not been disclosed.

His daughter-in-law Catherine, Princess of Wales, 42, underwent abdominal surgery in January and said in March that she was receiving chemotherapy.

Again, no details were given about what type of cancer she has. Kate, as she is widely known, is married to Charles’s elder son and heir Prince William.

Tuesday’s event, the first in a number of planned engagements in the coming weeks, is designed to raise awareness of the importance of early cancer diagnosis and highlight innovative research.