The World Health Organization (WHO) has appointed President Robert Mugabe of Zimbabwe as a "goodwill ambassador" to help tackle non-communicable diseases.
But critics say that during Mr Mugabe's 37-year rule Zimbabwe's health services have deteriorated, with staff regularly unpaid and medicines in short supply.
Dr Tedros, who is Ethiopian, is the first African to lead the WHO.
He was elected with a mandate to tackle perceived politicisation in the organisation.
Dr Tedros replaced Margaret Chan, who stepped down from her 10-year post in June.