Gabon is open to investment and wants to see its raw mineral resources processed locally, but needs large investments in energy to do so, the Central African country's President Brice Oligui Nguema told US President Donald Trump on Wednesday.

"We are not poor countries. We are rich countries when it comes to raw materials. But we need partners to support us and help us develop those resources with win-win partnerships," Nguema said at a mini-summit at the White House.

He warned other countries could seize the initiative if the US did not. "Our country is free, open to one and all. You are welcome to come and invest. Otherwise other countries might come instead of you," he said.