(BBC) - US President Barack Obama has arrived in Dar es Salaam in Tanzania, on the last leg of his African tour.
Mr Obama and his family were welcomed by his Tanzanian counterpart Jakaya Kikwete and troupes of dancers.
The president is being accompanied by hundreds of business executives and trade is expected to top the agenda.
Mr Obama will also visit an US-owned power plant, following his announcement over the weekend of a multi-billion-dollar electricity initiative.
The $7bn (£4.6bn) five-year initiative is intended to double access to electricity in sub-Saharan Africa, in partnership with African countries and the private sector.
Mr Obama made the announcement at South Africa's University of Cape Town after the US first family had visited Robben Island, the former jail where Nelson Mandela spent 18 years of his 27 years in captivity during his fight against the apartheid regime.
During his time in South Africa, the US leader did not visit the Mr Mandela, who remains critically ill in hospital suffering from a lung infection, but he did met the Mandela family in private.
Correspondents say roads have been closed and security stepped up in Tanzania's main city of Dar es Salaam for the US president's visit.
Ahead of his arrival, President Kikwete told the BBC's Newsday programme: "For development you need investments to utilise the huge potential that there is so that this huge potential can translate into incomes and jobs for our people and therefore development for our country."
On Tuesday, Mr Obama will lay a wreath at a memorial outside the US embassy in the main city, Dar es Salaam, in honour of 11 people killed in a bombing by al-Qaeda in 1998.
His wife, Michelle Obama, is expected to take part in African First Ladies Summit organised by the George W Bush Institute and hosted by her predecessor, Laura Bush.
Mr Obama's second tour to sub-Saharan Africa since becoming president began in Senegal where he called on African governments to give gay people equal rights by decriminalising homosexual acts.
The US president has excluded from his itinerary Kenya, where his father was born, and Nigeria, Africa's biggest oil producer which has been hit by an Islamist insurgency.