King Charles III has expressed his heartbreak over the death of former president of Tanzania Ali Hassan Mwinyi, calling him a “true friend” of the UK.

The cancer-stricken King, who continued his head of state duty, sent a written message to express his deepest sympathies to Mwinyi’s family.

The 75-year-old, in his heartfelt message to the president of Tanzania Samia Suluhu Hassan, wrote: “It was with great sadness that I learned of the death of former President Mwinyi.

“He was a true friend of the United Kingdom and the Commonwealth, and a leading figure in Tanzania’s economic and political development. I can only offer you my deepest sympathy at his passing.”

He added: “The United Kingdom was delighted to invite President Mwinyi to London in 1988, when he was hosted by my mother, Her late Majesty Queen Elizabeth II, for lunch at Buckingham Palace, and met prime minister Margaret Thatcher.

“I understand that this was his first official visit to Europe and he was able to make great strides in cementing the United Kingdom-Tanzania relationship.

“My special thoughts and prayers are with former President Mwinyi’s family and the Tanzanian people at this time.”

On Wednesday, The King also held diplomatic audiences at Buckingham Palace, receiving incoming Algerian ambassador Nourredine Yazid and the ambassador for Mauritania, Samba Mamadou Ba, who presented their credentials.