The monarch, along with wife Queen Camilla, will visit a cancer treatment centre in London on Tuesday, to speak with others patients and medical specialists.
“His Majesty is greatly encouraged to be resuming some public-facing duties and very grateful to his medical team for their continued care and expertise,” a Buckingham Palace spokesperson said on Friday evening (3am on Saturday AEST).
Among the list of upcoming activities will be a state visit to the UK by the Emperor and Empress of Japan in late June, which was also announced overnight.
The image of the couple was taken by portrait photographer Millie Pilkington in the Buckingham Palace garden on the morning of April 10 – the day after their 19th wedding anniversary.
Her Majesty is wearing an indigo day dress with velvet detail by Fiona Clare.
The King was last seen publicly with Queen Camilla at an Easter Sunday service at Windsor Castle, where the monarch briefly met with gathered crowds.
While the King is set to undertake a number of external engagements over the coming weeks, the palace has warned “it will not be a full summer programme” for His Majesty.
Appearances at his birthday parade, known as Trooping the Colour, along with Buckingham Palace garden parties and Royal Ascot will all be undertaken on a case-by-case basis.
First new photo from Kate to mark Prince Louis’ birthday
“Planning continues for ways in which Their Majesties may attend such Summer and Autumn engagements, though nothing can be confirmed or guaranteed at this stage,” the palace spokesperson said.
“All future plans remain subject to doctors’ advice nearer the time.”
They say forthcoming engagements will be adapted where necessary to minimise any risks to the monarch’s continued recovery.
King Charles announced his cancer diagnosis in February after the tumour was discovered during a procedure for an enlarged prostate in January.
While the type of cancer remains unspecified, the palace did say the monarch does not have prostate cancer.
The King’s daughter-in-law Catherine, Princess of Wales, is also currently undergoing treatment for an unspecified cancer, which was also discovered during a routine operation in January.
