The World Health Organisation has rescinded the appointment of Zimbabwean President Robert Mugabe as a goodwill ambassador after major Western donors and rights groups voiced outrage.

WHO Director-General Tedros Adhanom Ghebreyesus named Mr Mugabe to the largely ceremonial post at a high-level WHO meeting on chronic diseases, attended by both men, in Uruguay on Wednesday.

Mr Tedros praised Zimbabwe as "a country that places universal health coverage and health promotion at the centre of its policies to provide health care to all".

Several former and current WHO staff said privately they were appalled at the "poor judgement" and "miscalculation" by Mr Tedros, elected the first African head of WHO in May.

In a statement this afternoon, Mr Tedros said he had "decided to rescind the appointment" of Mr Mugabe. 

"Over the last few days, I have reflected on my appointment of H.E. President Robert Mugabe as WHO Goodwill Ambassador for NCDs in Africa. As a result I have decided to rescind the appointment," Mr Tedros said in a statement posted on his Twitter account.

Mr Mugabe was head of the African Union (AU) when the bloc endorsed Mr Tedros - a former health and foreign minister of Ethiopia - over other African candidates for the top post, without any real regional contest or debate, they said.

Mr Mugabe, 93, is blamed in the West for destroying Zimbabwe's economy and numerous human rights abuses during his 37 years leading the country as either president or prime minister.

Minister for Health Simon Harris described the appointment as "offensive" and "bizarre".

Britain said Mr Mugabe's appointment was "surprising and disappointing" and that it risked overshadowing the WHO's global work.

The United States, which has imposed sanctions on Mr Mugabe for alleged human rights violations, said it was "disappointed".

"He (Tedros) has to remember where his funding comes from," said one health official who declined to be identified.

The Trump administration, which is already questioning financial support for some programmes of United Nations agencies, is WHO's largest single donor.

The controversy came as WHO struggles to recover its reputation tarnished by its slowness in tackling the Ebola epidemic that killed more than 11,000 people in West Africa from 2014-2015 under Mr Tedros' predecessor Margaret Chan.

The Geneva-based agency is currently grappling with crises including a massive cholera outbreak in Yemen that has infected some 800,000 people in the past year and an outbreak of plague in Madagascar that has killed nearly 100 people in two months.