King Charles has been forced to cancel public engagements after being taken to hospital due to side effects from his ongoing cancer treatment, Buckingham Palace says.
A statement from Buckingham Palace said the 76-year-old "required a short period of observation in hospital" on Thursday morning UK time.
The palace said the king returned to Clarence House, but plans for him to travel to Birmingham for a series of public appearances on Friday had been scrapped.
Charles had been expected to visit the city's Royal Ballet, open a new hospital and visit a church and a Sikh temple, the BBC reported.
"Tomorrow, he was due to undertake four public engagements in Birmingham and is greatly disappointed to be missing them on this occasion," read a palace statement reported by the BBC.
"He very much hopes that they can be rescheduled in due course and offers his deepest apologies to all those who had worked so hard to make the planned visit possible."
The king's state visit to Italy is still set to go ahead from April 7 with some changes to the planned schedule, the palace said this week.
The palace did not detail what the king's side-effects were, and has never disclosed what type of cancer the king has.
The king's cancer was detected when he had treatment for an enlarged prostate in January 2024.
He stepped away from public duties until last April for a period of treatment and rest, but continued fulfilling state duties, such as reviewing government papers and meeting with the prime minister.
Charles's illness came as the Princess of Wales, Catherine, was also diagnosed with cancer.
ABC