Venezuela's President Hugo Chavez is in Benin as part of a tour aimed at strengthening ties with Africa. On Wednesday he visited Mali, where he promised $100m a year in petroleum products to help fight poverty.
Analysts say Mali and Benin could both benefit from Venezuelan money and know-how as they explore their territories for oil and gas reserves.
Mr Chavez is said to be seeking African support for Venezuela's bid for a seat on the UN Security Council.
"I will give Mali $100m a year in petroleum products and I do not want payment in cash. I don't want you even to say thank you," Mr Chavez said during his meeting with Malian President Amadou Toumani Toure, quoted by Reuters news agency.
"But I need your mineral products like bauxite, gold and fertiliser, and the rest of the total will help you combat poverty."
Benin is thought to have 4bn barrels of untapped oil reserves.
Mali is exploring for oil and gas on its northern frontier with Algeria, but as one of Africa's poorest countries, needs finance and expertise to achieve its goal.
African nations are seen to be central in Venezuela's attempts to secure a non-permanent UN Security Council seat, says the BBC's Greg Morsbach in the Venezuelan capital, Caracas.