King Charles is set to scale back his visit to Australia amid his ongoing treatment for cancer

A source told The Daily Mirror newspaper: "Naturally, it will be a bitter disappointment on both sides to not have the opportunity for the King and Queen to visit New Zealand.

"But all are aware of the King's ongoing health issues and the need for him to pace himself. It's very much hoped there will be further opportunities in the future."

Insiders say that the Australian leg of the tour will be reduced to six days - with a two-day break before Charles and Camilla travel to Samoa for the Commonwealth Heads of Government Meeting.

An itinerary for the Australia visit includes the King meeting people affected by devastating floods caused by Cyclone Jasper in January and the country's Prime Minister Anthony Albanese has confirmed that logistical planning for the royal tour is well under way.

He said: "The King has shown his compassion for Australians affected by recent natural disasters, just as Australians have shown compassion for the King following his cancer diagnosis."

Deputy Prime Minister Richard Marles added: "There is an affection for King Charles. I know King Charles has a deep affection for Australia."

Charles has a long connection to Australia dating back to the 1960s and would become the first sovereign to visit the country since his late mother Queen Elizabeth did so in 2011.

A palace source said: "Planning for an autumn tour continues subject to doctors' advice and any necessary modifications."