US Secretary of State Hillary Clinton says Africa has enormous economic potential, but warns that investors will shun African states with weak leaders and economies riddled with corruption and crime.

Ms Clinton made her statement at an economic summit in the Kenyan capital Nairobi attended by delegates from 40 African countries. She showed the delegates a video message from President Barack Obama. In it, he says that he would like to see closer trade ties with Africa and promised the continent his full support.

In Nairobi, The US secretary of state will meet with Somalian President Sheikh Sharif Ahmed. Kenya is the first stop on an eleven-day tour of Africa. After Kenya, Ms Clinton will travel on to South Africa, Nigeria, Angola, Liberia, the Democratic Republic of Congo and Cape Verde.