Britain’s Prince Harry has revealed that his father, King Charles, no longer speaks to him and that he cannot imagine bringing his family back to the UK after losing a court case over his security arrangements on Friday.

"I don't know how much longer my father has," the Duke of Sussex said of Charles, who was diagnosed with cancer last year.

Britain's King Charles will attend Canada's state opening of parliament in Ottawa, Buckingham Palace said on Friday, in a clear show of support for the former British colony of which he is still head of state.

In his first news conference since the federal election, Canadian Prime Minister Mark Carney laid out his priorities, including how he will approach forthcoming talks with US President Donald Trump. He also said he has invited King Charles III to formally open Canada's 45th Parliament later this month - the first time in decades that a reigning British monarch would preside over such an occasion.

King Charles will visit Ottawa to deliver the speech from the throne at the end of this month in a show of support for Canadian sovereignty, Prime Minister Mark Carney said Friday.