Some of the 50 leaders there fear the issue will push the crises in Zimbabwe, Somalia and Darfur off the agenda.

Zimbabwean President Robert Mugabe said unity was vital to make the continent truly independent of the West, as he spoke to a crowd of cheering Ghanaians.

"Until and unless we put our act together, and look at our resources, organise and start pooling our resources together, and we have lots of them, we will never, ever prosper from any aid from any source outside Africa," President Mugabe said on Sunday in a speech at the tomb of Ghana's first president.

Ghana's President John Kufuor said in his opening speech to the conference that the question of unifying Africa was not in doubt, but the key issue was how to attain it.

"I am confident that at the end of our deliberations, we should be able to arrive at a common understanding on the sort of continental government we want for ourselves, and a roadmap with timelines on its realisation," he said.

African Union Commission head Alpha Oumar Konare told the gathering that Africans needed to "take the bull by the horns and move towards a new country - Africa".

But campaigners on the sidelines of the summit, say delivery is the key problem, with leaders already having shown they are unwilling to give up power to regional economic blocs.

"We have regional economy communities that were put in place for West Africa,  but nothing is working. From one country to another,  there are still a lot of obstacles," a campaigner for the organisation Call To Action Against Poverty told the BBC.