King Charles to resume public-facing duties, but cancer treatment to ...

King Charles III will return to public-facing duties on Tuesday, just over 12 weeks after suspending them while receiving cancer treatment.

In a statement released at 6pm local time on Friday (3am AEST Saturday), Buckingham Palace said the King and Queen Camilla would make a joint visit to a cancer treatment centre, to meet specialists and patients.

A new portrait of the royal couple was also released on Friday, to mark the first anniversary of the King's coronation.

Buckingham Palace said the King's cancer treatment would continue, but that doctors had cleared him to resume public facing duties because they were "pleased with his progress".

The palace said it was "too early to say" how long the monarch's treatment would continue.

"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," the palace's statement read.

It's understood the cancer treatment centre that the royal couple will visit has not been directly involved in the King's treatment.

In a post on the social media platform X, British Prime Minister Rishi Sunak said the palace's announcement was "brilliant news to end the week".

King Charles suspended public-facing duties on February 5, after the palace revealed he had been diagnosed with cancer.

Doctors made the diagnosis after he was treated in hospital for an enlarged prostate.

While the palace has remained vague about the King's treatment and prognosis, it has previously confirmed the royal did not have prostate cancer.

Friday's statement said future engagements would be "adapted where necessary to minimise any risks to His Majesty's continued recovery".

However, it did confirm the King Charles and Queen Camilla would host the Emperor and Empress of Japan for a state visit in June.

The statement also did not rule out an overseas trip for King Charles later this year in the northern hemisphere autumn.

There has been speculation a potential voyage could include Australia, and Samoa, where the Commonwealth Heads of Government Meeting will be held in October.

"All future plans remain subject to doctors' advice nearer the time, with appropriate adaptations made where necessary to minimise any risks to His Majesty's continued recovery," the statement read.

The palace statement provided no update on the condition of the King's daughter-in-law Catherine, Princess of Wales, who has also been diagnosed with cancer.