Zimbabwean human rights activists have accused the World Health Organization of hypocrisy after it appointed Robert Mugabe as a goodwill ambassador.

Mr Mugabe, who regularly flies abroad for his own medical treatment and has been accused of running his country's health system into the ground, received the honour at a conference on non communicable diseases in Montevideo, the capital of Uruguay, on Wednesday.

Dr Tedros Adhanom Ghebreyesus, the head of the WHO, the branch of the United Nations responsible for health care, said Mr Mugabe had been chosen to advocate for better healthcare throughout Africa.

"I am honoured to be joined by President Mugabe, of Zimbabwe, a country that places universal health coverage and health promotion at the centre of its policies to provide health care to all," Dr Tedros said in an address to the conference.

"Today I am also honoured to announce that President Mugabe has agreed to serve as a goodwill ambassador on NCDs for Africa to influence his peers in his region to prioritize NCDs."