King Charles becomes Samoan 'high chief' and tries kava

King Charles has participated in a traditional kava drinking ceremony and been declared a Samoan "high chief" during his visit to the Pacific island nation.

The 75-year-old British monarch is currently on an 11 day tour of Australia and Samoa - his first major overseas trip since being diagnosed with cancer earlier this year.

He took part in a traditional kava-drinking ceremony with a group of bare-chested Samoans on Thursday.

The King and Queen Camilla visited the village of Moata'a, and he was made 'Tui Taumeasina', which means high chief.

And in the separate kava drinking ceremony on Thursday, kava roots were paraded around the tent.

He was presented with a half-coconut filled with the kava brew, which is slightly intoxicating and peppery, while the drink - which is known as "ava" locally - holds a special place in Pacific culture.

When the drink was ready, a Samoan man screamed as he decanted it, and then gave it to the king, who said "May God bless this ava" before taking a sip.

The king also toured a mangrove reserve to learn about the climate change impact on Pacific island nations, which are frequently battered by mega cyclones.

He has spent a lifetime raising awareness about environmental issues and has characterised global warming as the greatest threat to humanity.

The high chief title for Charles comes days after Australian indigenous crossbench Senator Lidia Thorpe accused the monarch of "genocide" during a protest at parliament in Canberra.

The king is in Samoa for the Commonwealth Heads of Government Meeting.

Britain has flagged it won't raise the issue of reparations for historic slavery at the leaders' summit.

In February, Buckingham Palace announced that Charles had been diagnosed with "a form of cancer".

The king underwent a "corrective procedure" for an enlarged prostate and doctors noticed a "separate issue of concern" that led to his cancer diagnosis.

The king - who recently spent six days in Australia - is said to be in "good spirits".

Royal biographer Robert Hardman told PEOPLE that Charles appreciated having the support of Camilla, 77, on the royal tour.

"She keeps his spirits up and is a reassurance, but she also steps in here and there," Robert said.

"We know she is not particularly keen on long-haul travel and yet has thrown herself into this trip."