The US has increased its military interests in Africa in recent years
The US has launched a new command centre for military operations in Africa, in a sign of a clear increase in American interest in Africa.
Known as Africom, the initiative was first announced in February and will be based initially in Stuttgart, Germany.
Until now responsibility for Africa has been divided among the US military's European, Central and Pacific commands.
The Pentagon says Africom will allow the US to have a more integrated and effective approach to the continent.
This is a significant re-ordering of the US military, and an increased interest that can be explained in three words - oil, terrorism and instability.
The US now gets over 10% of its oil from Africa and is concerned about competition from China.
It is also worried about the potential threat from Islamic extremists in failed or failing states.
But Africa is not about to see an explosion in US bases and airstrips.
The Pentagon is being careful to stress the aim of the new command is to help struggling states through training and aid, and not to launch new wars.
It points out that over one-third of approximately 400 or so staff will be diplomats and aid specialists rather than uniformed military.
The initiative has received mixed reviews in the US.
Though many analysts welcome it as an opportunity for a more intense and unified approach to Africa, others warn of what they see as the danger of the militarisation of US policy towards the continent.
In Africa itself the response has been guarded.
Although the US has been strengthening its security ties with a number of African nations over the last few years many are cautious about being seen to embrace the Americans too warmly - at least in public.
That is one reason, perhaps, why the Pentagon has yet to find an African country willing to host the headquarters for Africom, despite a considerable amount of shopping around.
By Rob Watson
BBC News defence and security correspondent