Prince Harry has suggested that King Charles's illness could help reunite the British royal family, and described how he immediately "jumped on a plane" to London after his father's cancer diagnosis.

In an interview with ABC's Good Morning America show on Friday, the prince made his first public comments on the king's health.

He said he heard the news directly from Charles "and went to go and see him as soon as I could."

"I love my family," Harry said, adding he was "grateful" to spend a brief amount of time with his father last week.

Harry spoke in Canada where he and his wife Meghan are attending training a year ahead of the Invictus Games for injured military veterans, an event that he organizes.

Asked if the illness could bring his family back together, Harry said "Yeah, I'm sure."

Referencing the games, he added that "throughout all the families that I see on a day-to-day basis (it is) the strength of the family unit coming together."

Harry declined to give details on his father's health, saying "that stays between me and him."

Prince Harry quit royal duties in 2020 and relocated to California where he lives with his American wife and their two young children.

"I have got other trips planned that would take me through the UK, or back to the UK so I will stop and see my family as much as I can," said Harry.

He also said he had considered seeking American citizenship, but it was not a current priority for him.

Charles' diagnosis came just 17 months into his reign following the death of his 96-year-old mother, Queen Elizabeth II, on September 8, 2022.