GENEVA (AP) — Health ministers, diplomats and other high-level envoys are set to choose the next director-general of the World Health Organization among three finalists.

As it stands, 185 member states attending WHO's World Health Assembly are eligible to cast ballots Tuesday afternoon. Nine others are either in arrears on their dues or not represented at the 10-day gathering.

The candidates are Tedros Adhanom Ghebreyesus, a 52-year-old former government minister in Ethiopia; Sania Nishtar, a 54-year-old cardiologist and former government minister from Pakistan; and David Nabarro, 67, a physician and longtime U.N. official from Britain.

The winner will succeed Dr. Margaret Chan, who's ending a 10-year tenure.

The U.N. agency's chief has considerable power to set global medical priorities and declare health emergencies, such as outbreaks of the Zika or Ebola viruses.