A declaration about the importance of safeguarding the oceans is expected to mark the conclusion of the Commonwealth Heads of Government Meeting on Saturday.
Climate change, slavery reparations, and the rule of law have also been major topics signalled ahead of the meeting. The representatives from the 56 Commonwealth countries who have gathered in Samoa for the meeting will be in discussions for about six hours.
They were officially welcomed by King Charles on Friday. He spoke about climate change as an existential threat and highlighted the Commonwealth's shared belief in the rule of law.
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His speech was preceded by that of the Commonwealth secretary general Patricia Scotland, who said the grouping's strong foundation of reform had led to it being an "influential and indispensable" resource for good in the world.
She also spoke about what she said was the "essential paradox" of the modern world, where people were more connected than ever, but where the world also seemed more dangerous.
Christopher Luxon at the Commonwealth Heads of Government Meeting opening ceremony on Friday. Photo: AFP / Manaui Faulalo
The togetherness of a group of disparate nations was what highlighted the strength and value of the Commonwealth, she said - also pointing to estimates that trade in the member countries was expected to top a trillion dollars by 2026, and double that in 2030.
Prime Minister Christopher Luxon committed earlier in the week to supporting the oceans declaration.
He had also previously spoken about wanting to connect more with countries that New Zealand had traditionally not engaged with so much in the past, including African and Caribbean countries.
However, a push for reparations for slavery by a grouping of 15 of those Caribbean nations appeared unlikely to gain support - at least from Luxon's Deputy Prime Minister Winston Peters.
Peters had on Friday said that "when the Europeans arrived in my country, my people were practising slavery. We're not going to deny the facts ... we're not going to start preaching to others when we were doing it ourselves".
However, he also saw value in the Commonwealth - and hoped it would become a stronger font of cooperation.
"I've always over the years wanted to see them to far, far more with the Commonwealth than they have done," he said.
"Far more economic cooperation, far more academic cooperation, far more medical cooperation."
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