US President Barack Obama urges Africa to end 'cancer of corruption'

US President Barack Obama called on Africa Tuesday to end "the cancer of corruption" and embrace democracy to ensure continued progress, in a speech to the African Union.

"Nothing will unlock Africa's economic potential more than ending the cancer of corruption," Obama said, warning that it drained "billions of dollars" from economies that could be used for health systems or creating employment.

"Only Africans can end corruption in their countries," he said.

But he also said that ensuring democratic rights were protected was key.

"Africa's progress will also depend on democracy, because Africans, like people everywhere, deserve the dignity of being in control of their own lives," he said, in a speech that closes his two-nation tour of Kenya and Ethiopia.

"Yet at this very moment, these same freedoms are denied to many Africans. I have to proclaim, democracy is not just formal elections," he added, to cheers from the packed hall, with all its 2,500 seats taken by AU officials as well as civil society representatives.

"When journalists are put behind bars for doing their jobs, or activists are threatened as governments crack down on civil society, then you may have democracy in name, but not in substance.

"I am convinced that nations cannot realise the full promise of independence until they fully protect the rights of their people."