King Norodom Sihamoni and Queen Mother Norodom Monineath Sihanouk sent a letter of both condolences and congratulations to King Charles III of the United Kingdom of Great Britain and Northern Ireland on his recent accession to the throne following the death of his mother, Queen Elizabeth II.

“On the auspicious occasion of Your Majesty’s official proclamation as King of the United Kingdom of Great Britain and Northern Ireland by the Accession Council, I would like to extend to Your Majesty my warmest congratulations and best wishes for Your Majesty’s future wellbeing as well as for the great prosperity of your country and happiness of all your loyal subjects,” King Sihamoni stated in the letter dated September 12.

"I am confident that the existing excellent bonds of friendship and cooperation between our two kingdoms and peoples will continue to prosper under Your Majesty’s reign," the letter continued.

The Prince of Wales was proclaimed King Charles III on September 10 after Queen Elizabeth II passed away two days prior at the age of 96.

On September 12, Prime Minister Hun Sen paid tribute to the late Queen Elizabeth II at the British embassy in Phnom Penh, writing in their condolences book that he was filled with "profound grief" to have learned of the passing of the Queen at Balmoral Castle in Scotland. He said the demise of Queen Elizabeth II was not only a great loss to the UK and the Commonwealth, but also to the world at large.

The late Queen, Hun Sen wrote, emerged as a beloved public figure through her reign, her discipline and the ways she inspired people and that she will forever be remembered in the hearts of all of the British people and the hearts of many others around the world.

“In this moment of deepest sorrow, and on behalf of the royal government and the people of Cambodia, we express our condolences for this immense loss to the bereaved families of the Royal Households. May her soul rest in peace,” he wrote.