The King, aged 75, is optimistic about being able to embark on the trip, which would incorporate visits to New Zealand and Samoa, where the annual Commonwealth Heads of Government meeting (Chogm) is scheduled to take place.
The Palace aides are reviewing the proposed itinerary and will start making preliminary arrangements in the upcoming weeks, with pending site visits in the plans.
However, it was emphasized by sources that it is still early days, and the feasibility of such future trips greatly depends on the King's response to the ongoing treatment in the following months.
“There is a strong desire from the King to attend Chogm if his health permits,” remarked one source.
“Progress is being made with his treatment and things are moving in a positive direction.
" "If he is medically fit to travel, he will certainly do so.
Planning is ongoing, but it is crucial to remember that nothing is guaranteed at this point.
We are still some time away from final decisions.
” Reports indicate that the King is feeling "optimistic" about resuming his public duties after a promising initial response to his cancer treatment.
His appearance at the traditional Easter Matins service at St George’s Chapel, Windsor, was considered a significant milestone, with his medical team expressing great hope and positivity for his recovery.
During the service, the King warmly greeted well-wishers, shaking hands and expressing gratitude for their support, assuring them that he is giving his best effort.
Diagnosed with an undisclosed form of cancer in January, the King commenced weekly treatment right away, leading to such positive results that his doctors modified their recommendations regarding his ability to undertake public engagements.
The King is aiming to attend Trooping the Colour on June 15, his official birthday celebration, and the 80th anniversary commemorations of D-Day the week before.
Nonetheless, there is a continuous emphasis on the cautious approach due to the ongoing treatment, and it remains a priority to prioritize his health and well-being.
The highly-anticipated state visit to Australia would be alongside the Queen, marking the King's first official trip to the country since his enthronement and the first by a reigning monarch since Queen Elizabeth II in October 2011.
An invitation awaits him to attend the Melbourne Cup on Nov 5, an event that holds significance as he first went there with Princess Diana in 1985 and later returned with Camilla, the Duchess of Cornwall, in 2012.
Additionally, the King is invited to The Everest race day in Sydney on Oct 19, where he is anticipated to present the trophy for the King Charles III Stakes race named in his honor.
The trip would likely encompass participation in the bicentenary celebrations of the New South Wales parliament’s upper house, and prospective visits to attractions like Taronga Western Plains Zoo in Dubbo, the iconic Queen Victoria Building in Sydney, and the Opera House.
However, there are considerations for a more condensed tour lasting around two weeks, as opposed to the initially planned three weeks.
A potential visit to Fiji has been ruled out, and adjustments would be made to the King's schedule to include substantial periods of rest and recuperation.
The Commonwealth Heads of Government meeting is scheduled to take place from Oct 21 - 25.