King Charles is reportedly taking two doctors and a supply of his blood on his upcoming tour of Australia and Samoa.

The monarch, 77, who has been battling an undisclosed form of cancer since February, will apparently have the medics on standby 24 hours a day during his upcoming nine-day royal trip starting on Friday.

Charles will be "monitored closely during the visit", with a palace source adding Michael Dixon – head of the royal medical household and known for his interest in homeopathy – "will not be travelling" with His Majesty, according to a report in The Times.

(Charles and Camilla arrive on Friday for their first Commonwealth tour since ascending the throne. (AP PHOTO)

Charles' visit to Sydney and Canberra will be his first to a Commonwealth realm since becoming king and it's understood he is pausing his chemotherapy treatment until after the trip.

The Times added steps taken to support Charles abroad are "the same as arrangements put in place for the late Queen". 

They will also apparently include travelling with a supply of the king's blood to ensure a match if a transfusion was needed, The Times said.

As well as travelling with his own doctors, the king will be supported by medical teams during the entire trip. 

In Australia, Charles' itinerary will include a rest day and there will be no evening engagements.

But Charles and his wife Queen Camilla, 77, will arrive in the evening in Samoa and are due to attend a state dinner. 

Buckingham Palace said in April Charles was "greatly encouraged" by news from his doctors he could resume public duties while his treatment continued. 

Despite the encouraging signs over Charles' health, a planned visit to New Zealand was dropped from the upcoming tour.

Charles told the nation's female rugby squad at a reception for them in Buckingham Palace in September: "I'm extremely sorry I can't come to New Zealand in later October – it's on doctors' orders. 

"But I hope there will be another excuse (to come) before too long. 

"In the meantime, give my love to New Zealand."