Image copyright Reuters Image caption Drone use has risen under President Obama

US drone and air strikes have killed between 64 and 116 civilians outside war zones since 2009, the White House says.

The numbers, covering the period from January 2009 to December 2015, are significantly lower than estimates by human rights groups.

Some groups say that several hundred civilians have died in US strikes.

The long-promised report was released in conjunction with an executive order to increase civilian safeguards.

President Barack Obama signed the executive order to require the government to disclose the number of civilian deaths each year in an effort to improve transparency in US military operations.

The directive, which could be cancelled by the next president, requires government reviews of air strikes to include "credible reporting" by non-governmental groups.

Human rights groups have long accused the US government of obscuring the number of civilian casualties in drone and air strikes.

'Misinformation'

The London-based Bureau of Investigative Journalism estimates between 492 and 1,100 civilians have been killed by drone strikes in Pakistan, Yemen and Somalia since 2002.

It says its figures are based on reports by local and international journalists, NGO investigators, leaked government documents, court papers and the result of field investigations.

But the Obama administration cautioned that figures from human rights groups could be flawed due to the "deliberate spread of misinformation by some actors, including terrorist organisations, in local media reports on which some non-governmental estimates rely".

The order also makes civilian protection a priority.

The assessment revealed that between 2,372 and 2,581 members of terrorist groups were killed in the 473 strikes since Mr Obama took office in 2009.

The White House declined to disclose where the civilian deaths occurred, but said the numbers excluded countries such as Afghanistan, Iraq and Syria.

The estimates do not include civilians killed during military operations when American forces are on the ground.