The World Health Organization is rethinking its decision to appoint Zimbabwean president Robert Mugabe as a "goodwill ambassador" following widespread shock and condemnation.
WHO gave Mugabe the role claiming the 93-year-old leader had made a "commitment to public health".
This is despite his alleged record of human rights abuses.
Zimbabwe's main opposition party Movement for Democratic called the appointment by new WHO director general Dr Tedros Tedros Adhanom Ghebreyesus an "insult".
Spokesman Obert Gutu said: "Mugabe trashed our health delivery system. He and his family go outside of the country for treatment in Singapore after he allowed our public hospitals to collapse."
WHO director-general Tedros Ghebreyesus said: "I'm listening. I hear your concerns. Rethinking the approach in light of WHO values. I will issue a statement as soon as possible."
Mr Tedros, an Ethiopian who became the WHO's first African director-general this year, said Mugabe could use his role "to influence his peers in the region".
He claimed Zimbabwe was "a country that places universal health coverage and health promotion at the centre of its policies to provide healthcare to all".
But despite once being known as the breadbasket of southern Africa, in 2008 a charity released a report documenting failures in Zimbabwe's health system and blamed Mugabe for policies that led to a man-made crisis.
Physicians for Human Rights found his government had "presided over the dramatic reversal of its population's access to food, clean water, basic sanitation and health care".
It went on: "The Mugabe regime has used any means at its disposal, including politicising the health sector, to maintain its hold on power."
The report said Mugabe's policies had led to "the shuttering of hospitals and clinics, the closing of its medical school and the beatings of health workers".
Downing Street said it had raised concerns with WHO calling Mugabe's appointment "surprising and disappointing particularly in light of the current US and EU sanctions against him".
The US called the appointment of Mr Mugabe by WHO's first African leader disappointing.
Health and human rights leaders chimed in.
"The decision to appoint Robert Mugabe as a WHO goodwill ambassador is deeply disappointing and wrong," said Dr Jeremy Farrar, director of the Wellcome Trust, a major British charitable foundation.
"Robert Mugabe fails in every way to represent the values WHO should stand for."
Ireland's health minister, Simon Harris, called the appointment "offensive, bizarre", while Kenneth Roth, the head of Human Rights Watch, tweeted: ''Mugabe corruption decimates Zimbabwe health care."