The Duke of Sussex has spoken with the King and will travel to the UK to see him in the coming days.

This follows the announcement that King Charles has been diagnosed with a form of cancer, which Buckingham Palace confirmed was discovered during his treatment for an enlarged prostate.

The exact type of cancer remains undisclosed.

However, the palace has announced that the King has begun regular treatments.

Read more: King Charles diagnosed with cancer - reaction from Sussex

Prince Harry has spoken with the King and will travel to the UK to see him in the coming days, BBC News has been told.

“The duke did speak with his father about his diagnosis. He will be traveling to UK to see His Majesty in the coming days,” the source close to Prince Harry said.

In light of his diagnosis and treatment, the King will postpone his public engagements.

The Argus: File photo dated 04/08/00 of Prince William (Duke of Cambridge), King Charles and Prince Harry (Duke of Sussex) on the balcony of Buckingham Palace, in London for the celebrations to mark the 100th birthday of Queen Elizabeth, the Queen MotherFile photo dated 04/08/00 of Prince William (Duke of Cambridge), King Charles and Prince Harry (Duke of Sussex) on the balcony of Buckingham Palace, in London for the celebrations to mark the 100th birthday of Queen Elizabeth, the Queen Mother (Image: PA)

Buckingham Palace anticipates that other senior royals will help to stand in during his absence.

As yet, there are no further details about the extent of the cancer or the King's prognosis.

Despite being diagnosed with cancer, the King remains positive about his treatment and is eager to resume full public duties as soon as he can.

The palace has reported that the King, while taking a break from public events, will continue in his constitutional role as head of state, including handling paperwork and private meetings.

When the head of state is unable to perform official duties, a constitutional mechanism allows for "counsellors of state" to be installed as stand-ins.

Currently, these include Queen Camilla, Prince William, Princess Anne, and Prince Edward.

Prince William previously took a temporary step back from public engagements while he assisted his wife, Catherine, the Princess of Wales during her recovery from abdominal surgery.

The palace announced earlier this week that he would resume public duties soon.

The king, 75, returned to London on Monday from Sandringham in Norfolk, where he had been seen at a church service the day before.

The King voluntarily disclosed his prostate condition with the intention of encouraging more men to undergo prostate checks.

Prime Minister Rishi Sunak, alongside Labour leader Sir Keir Starmer, has expressed wishes for the King's full and swift recovery.

In a briefing, the Palace said: “His Majesty has been treated for benign prostate enlargement. It was during this intervention that a separate issue of concern was noted and subsequently diagnosed as a form of cancer. This second condition will now receive appropriate treatment.

“No further details are being shared at this stage, but His Majesty is receiving expert care and looks forward to returning to full public duty as soon as possible.”

The briefing note added: “His Majesty is grateful to his medical team for their expert care and swift intervention, is wholly positive about his treatment and looks forward to returning to full public duty as soon as possible.”

At that time, the Palace told the public: “In common with thousands of men each year, the King has sought treatment for an enlarged prostate.

“His Majesty’s condition is benign, and he will attend hospital next week for a corrective procedure. The King’s public engagements will be postponed for a short period of recuperation.”

The King was eventually discharged after spending three nights in a Central London hospital.

Following his stay at the medical facility, a spokesman said: “The King was this afternoon discharged from hospital following planned medical treatment and has rescheduled forthcoming public engagements to allow for a period of private recuperation.”

Sources close to the Royal Family praised The London Clinic for the security measures put in place during Charles and Kate Middleton's stay.