King Charles arrives in Samoa on Wednesday ahead of a Commonwealth summit, hoping to breathe new life into a bloc seen by critics as "a leftover of empire".
This year's Commonwealth Heads of Government Meeting takes place in Apia, the coastal capital of Samoa, halfway between New Zealand and Hawaii.
The biennial meeting between 56 world leaders is expected to attract around 3,000 delegates, but the most high-profile guests will be King Charles and Queen Camilla, fresh from their tour of Australia.
The conference is the first hosted by a Pacific Island nation and will be an "extraordinary" opportunity to showcase the region, Commonwealth Secretary-General Patricia Scotland told AFP.
Scotland hopes the summit will "cement" the Commonwealth family "as we look to what, for many, is a very troubled and complex future".
"We have two choices globally. We can either swim together or we can drown separately," she said.
"The Commonwealth has never been for drowning. It's always been for fighting."
Scotland's sentiment is reflected in the theme of this year's summit: "One Resilient Common Future", with discussions to focus on the environment, democratic systems, economy, youth, gender and digital transformation.
Climate change and rising sea levels are expected to feature heavily, with world leaders to deliberate on an Ocean Declaration which will aim to prioritise initiatives for a healthy and resilient ocean.
There is no place like the Pacific nations to best highlight this "existential threat", Scotland said.
Once seen as the embodiment of palm-fringed paradise, the South Pacific is now one of the most climate-threatened pockets of the planet.
Many communities in the region have been forced to relocate to higher ground as rising seas swallow their homes.
About 70 percent of Samoa's population lives in low-lying coastal areas.
Samoa has spent months preparing for the summit, including renovating hotels and running a two-month gun amnesty to ensure the safety of world leaders and summit attendees.
The scheme offered illegal gun owners US$36 in grocery vouchers if they surrendered their firearms.
Each Commonwealth country has been adopted by a village, which has been decorated in that country's colours and national flags.
Samoan resident Mata'afa Keni Lesa told AFP he was "very excited" to show off "the best of our Samoan hospitality".
While some critics question the relevance of the Commonwealth in a post-colonial era and say it is "a leftover of empire", Scotland said this was far from true.
The last two countries to join the Commonwealth in 2022 -- Gabon and Togo -- were former French colonies.
And the Commonwealth was founded on the "most important human aspects" of friendship, commitment and integrity, giving every country an equal voice, Scotland said.
King Charles said in Canberra on Monday that the Commonwealth played a "significant role" on the world stage.
"It has the diversity to understand the world's problems, and the sheer brain power and resolve to formulate practical solutions," he said.
The summit also provides countries with an opportunity to meet without being overshadowed by "geostrategic anxiety or competition", said Tess Newton Cain of Griffith University's Asia Institute.
"There is no question that the tension and competition between the US and China plays out in Commonwealth counties," she said.
"I imagine there is a bit of relief that the US and China aren't there throwing their weight around."
Nonetheless, the legacy of empire will loom over the summit, in particular when leaders select a new secretary-general nominated from the African region -- in line with regional rotations of the position.
Scotland has been secretary-general since 2016, and all three candidates to succeed her have called publicly for reparations for slavery and colonialism.
The candidates are Joshua Setipa from Lesotho, Shirley Ayorkor Botchwey from Ghana and Mamadou Tangara from the Gambia.
