The World Health Organization’s decision to name President Robert Mugabe of Zimbabwe a “good-will ambassador” has provoked outrage from medical professionals, rights groups, opposition leaders and others who took to social media to call it an “insult” and “a sick joke.”

The 93-year-old African leader, who has long faced United States sanctions over his government’s human rights violations, received the title in Montevideo, Uruguay, this past week from the W.H.O.’s director general, Tedros Adhanom Ghebreyesus.

Dr. Tedros said he was “honored” to be joined by Mr. Mugabe, who could use the role “to influence his peers in his region” when it came to fighting noncommunicable diseases — such as heart attacks, strokes and asthma — in Africa. The W.H.O. leader was speaking at a global conference that ran from Wednesday to Friday.

He also lauded Zimbabwe as “a country that places universal health coverage and health promotion at the center of its policies to provide health care to all.”