On a visit to Senegal, the US Secretary of State Mike Pompeo has overseen the signing of several private sector deals with American firms.
The road building, power and healthcare projects were announced at a time when China and Russia are deepening their political and economic ties across the African continent.
Later this month in Senegal and Mauritania, 1,600 troops from various African countries are due to take part in an American-led military training exercise focusing on countering Islamist extremist groups.
The US has indicated it intends to scale back its troop presence in Africa.
The move has been criticised by France which is leading the international response to the growing threat of jihadist violence in the region.