King Charles and Queen Camilla arrive at lavish Commonwealth dinner on last night in Samoa

spoke of his lifelong aspiration to visit every country in the Commonwealth as he hosted an official dinner for the Commonwealth Heads of Government on his final night in Samoa.

But he said that the ever expanding number of member states and his doctors' orders during his ongoing cancer treatment has prevented him from acheiving his aim so far.

Since 1969, Charles has visited 46 of the 56 Commonwealth countries, many of them on several occasions.

During the only evening engagement of the King and Queen's 10-day visit to Australia and the Pacific, Their Majesties hosted delegates from the Commonwealth Heads of Government meeting at the former home of Robert Louis Stevenson in Samoa where the biannual summit is being held.

Palace aides have spent almost two years planning the welcome dinner and a Palace source said it had been the most "technically complex dinner" they have put on.

Charles, 75, ditched the suit and tie he was wearing earlier for a Red Sea rig dress with Samoan detail from the Samoan school of fine art.

In a matching shade of blue, Camilla, 77, wore an embroidered tunic top and blue palazzo trousers by Anna Valentine with diamond earrings.

Their Majesties stood on the museum's veranda and greeted the 80 guests in turn, which included Sir Keir Starmer.

The High Commissioner of Canada was heard apologising for the non-appearance of the Justin Trudeau, the prime minister of Canada, saying: "It's the first time he's ever missed it."

When the King met Nana Akufo-Addo, the President of Ghana, who attended the dinner in black tie, Charles told him: "You're making me feel underdressed."

In a speech, the King borrowed a phrase from the Scottish author, saying: "One should not judge each day by the harvest you reap but by the seeds that you plant."

Charles said he first visited Samoa in the 1970s and spoke of his "joy" of returning to the country to deepend his understanding of the country.

He said hat the singing by local performers at the opening ceremony of the Commonwealth summit earlier in the day had "raised my spirits to the roof and made me feel unbelievably happy".

The King went on to speak warmly of his affection for the family of nations, saying "The Commonwealth can surely be a source of hope".

He added that while "dark clouds gathered", international challenges required international solutions and that "dialogue and discussion" was the way to achieve peace.

Before taking to his feet in a more informal, pre-dinner speech in the evening, two toasts by the President of Sierra Leone and the President of Guyana were given in his honour.

In the second toast, Dr Irfaan Ali of Guyana praised the King's "willingness to engage in difficult conversations that will enable us to learn from a sometimes difficult past while we carve a future as a commonwealth of equal partners."

Inside the marquee, guests sat at round tables decorated with traditional Samoan bowls, napkins printed by EKFS School of Fine Arts and Museum and Siapo printed table centres.

The 18 carat gold, silver-gilt, ruby, enamel Commonwealth Mace, which was presented to the late Queen in 1992 on the 40th anniversary of her accession to the throne, was placed on a hand-made table by the EKFS school.

The legs were crafted to symbolize the saying 'We stand on the shoulders of giants'

honouring our ancestors.

For the meal, the King sat between the leaders of Samoa and Guyana, while the Queen had the had of state of the Republic of Ghana and the Prime Minister of New Zealand on either side of her.

They tucked into a meal of local, seasonal produce, that included a salad of local vegetables, line caught red snapper and coconut jam cheesecake.

Guests washed down the meal with four different wines from New Zealand and Australia.

The dinner, which was not referred to as a banquet as it contained three courses rather than the usual four, marked the only late-night engagement of his long-haul trip.

The two trips were scaled back to safeguard his health, with his cancer treatment set to resume upon his return to the UK early next week.