The former President of Liberia, Charles Taylor, has arrived by plane in the Nigerian capital, Abuja.
Mr Taylor, who resigned from power earlier today, is expected to stay in exile in Nigeria, which has offered to grant him asylum.
Mr Taylor resigned following pressure from the United States to end more than a decade of civil war and regional instability.
During a formal ceremony the vice-president, Moses Blah, was sworn in as the new president.
It is understood Mr Blah will remain in power until October before handing authority to an interim administration.
In his speech, Mr Blah called on the west African regional grouping, ECOWAS, to fully deploy its peacekeeping force to ensure security in Liberia. He also urged the United States to deploy troops in the country.
Humanitarian organisations are anxious to resume supplies of food and medical aid to tens of thousands of people who have been isolated by weeks of fighting.
