The cholera epidemic has killed at least 9,300 people since 2010, when UN peacekeepers sent in the aftermath of Haiti's devastating earthquake dumped infected sewage into a river.
Outgoing UN Secretary General Ban Ki-moon apologised on Thursday for the role played by UN peacekeepers in starting an ongoing cholera outbreak in Haiti which has so far infected 800,000 people and killed at least 9,300.
"We simply did not do enough with regards to the cholera outbreak and its spread in Haiti," Ban said. "We are profoundly sorry for our role."
No significant outbreaks of cholera had ever been recorded in the impoverished Caribbean country before 2010, when peacekeepers were sent to help stabilise the situation in the aftermath of an earthquake which killed at least 100,000 people.
"We are profoundly sorry for our role" - Ban Ki-moon's message to the people of Haiti on the new UN approach to cholera (in Creole/kreyl). pic.twitter.com/VkuL2IBqXp— United Nations (@UN) December 1, 2016
Although the exact cause of the epidemic is still contentious, an independent panel appointed by Ban said in 2013 that Nepalese peacekeepers who dumped sewage into a river were the "most likely source" of the outbreak.
Cholera, which often causes severe diarrhoea that can lead to death through dehydration, is spread through water and food which has come into contact with contaminated human faeces.
The epidemic was made worse by Haiti's lack of public health and sewage infrastructure, unsanitary conditions in camps hosting people who lost their homes in the earthquake, and hurricanes which caused the bacterium to spread through floodwater.
The UN has refused to accept legal responsibility for the effects of the cholera epidemic, a position which UN Special Rapporteur on Extreme Poverty and Human Rights Philip Alston said in an October report "flouted the applicable international law" and "undermined the credibility of the organisation."
Ban's apology comes as he prepares to leave office at the end of his term on December 31. It also comes after a US federal appeals court upheld the UN's immunity in August in relation to the outbreak, meaning it is cannot be taken to court by those affected.
The international body has said it hopes to raise $200 million for families of the victims.