King Charles III, who suffers from cancer, spent the night from Monday to Tuesday at home after beginning outpatient treatment for the disease, which Prime Minister Rishi Sunak said was "detected early."
Speaking to the BBC, Sunak said he is in "regular contact" with the king and is grateful that the disease has been "detected early."
On Monday, Buckingham Palace announced that the cancer was discovered during the king's recent treatment for a benign enlarged prostate.
The Palace has not said what type of cancer the king has been diagnosed with.
The monarch has postponed his public duties, but
will "assume state functions"
and will continue to meet weekly with the prime minister.
Harry travels to London
Prince Harry left California on Monday night to travel to the United Kingdom to see his father.
This Tuesday, Harry's arrival was expected in London.
His car was seen at Los Angeles' main airport, known as LAX, on Monday night.
Shortly after Buckingham Palace's announcement on Monday, Prince Harry's team said he would travel to the UK to see his father, while his wife Meghan
would stay in California with their two children.
The flight between California and London takes about 11 hours.
While Harry's relationship with his family has been strained since moving to the United States, he continues to have a bond with his father.
Much or little information?
For experts on the British royals, the report on the king's cancer is almost news.
Long ago, a statement like this was unthinkable from a hermetic monarchy jealous of his privacy.
Simon Lewis, former press secretary to Queen Elizabeth II, says Buckingham Palace's statement on Monday night
was "spot on".
Even 20 years ago, all we would have received was
a "very curt, short statement,"
he says.
And although the type of cancer has not been revealed,
the Palace went as far as possible
, Lewis explained to the Today show.
"The most important point," adds Lewis, was that the Palace confirmed that the King would continue with his state duties and procedures.
With information from BBC News