The 75-year-old British monarch is currently in Australia and Samoa on an 11-day tour - his first major overseas trip since being diagnosed with cancer earlier this year - and he made his first speech as Head of Commonwealth during the opening ceremony for the Commonwealth Heads of Government Meeting in Apia.
The king expressed in his speech that "no one can change the past" but leaders could commit to learning from mistakes as they move forward.
He said: "None of us can change the past. But we can commit, with all our hearts to learning its lessons and to finding creative ways to right inequalities that endure.
"Nothing, it seems to me, would do so more decisively than to champion the principle that our Commonwealth is one of genuine opportunity for all.
"It is vital, therefore, that we understand our history -to guide us to make the right choices in the future. Where inequalities exist, for example, in access to opportunity; to education; to skills training; to employment; to health; and to a planet in whose climate our human race can both survive and thrive, we must find the right ways, and the right language, to address them.
"As we look around the world and consider its many deeply concerning challenges, let us choose within our Commonwealth family the language of community and respect, and reject the language of division."
During the king's tour, he has also been declared a Samoan "high chief" and he took part in a traditional kava-drinking ceremony with a group of bare-chested Samoans.
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 (24.10.24), 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.