The United States government has inadvertently killed up to 116 civilians in strikes in countries where the US is not at war, President Barack Obama has announced.
The major disclosure on Friday is likely to inflame debate about targeted killings and use of drones.
The estimate is higher than any previously acknowledged by his government but vastly below private estimates.
Obama's goal for the release of the numbers is to create greater transparency about what the US military and CIA are doing to fight militants plotting against the United States.
Non-governmental organisations (NGOs) estimate that hundreds of civilians were killed in such strikes, many of them by drones, in countries including Pakistan, Yemen and Somalia.
Obama's administration acknowledged "inherent limitations" in its ability to collect data in dangerous target areas but strongly defended its estimates.
It also cautioned that NGO figures could be flawed, citing "deliberate spread of misinformation by some actors, including terrorist organisations, in local media reports on which some non-governmental estimates rely".
Drone advocates, including those within the U.S. military, argue the strikes are an essential part of reducing the ability of militant groups to plot attacks against the United States.
They say the government goes to great lengths to avoid civilian casualties.
Critics of the targeted killing program question whether the strikes create more militants than they destroy.
They cite the spread of jihadist organisations and militant attacks throughout the world as evidence that targeted killings may be exacerbating the problem.