At the opening ceremony of a major US-Africa trade summit in Johannesburg, he said: "Africa is an important source of critical raw materials, but we do not want to be defined as simply the producers of commodities."

He added that African countries would profit greatly from keeping these materials in-house and transforming them into goods that can then be sold globally, rather than exporting the resources to countries with greater manufacturing capabilities.

"We look forward to the United States working with African countries to foster an investment-led approach that aims to diversify international supply chains of critical minerals by beneficiating these resources here on the African continent," Mr Ramaphosa said.

In terms of natural resources, Africa is the most abundant continent on earth. It has 40% of the world's gold, according to the UN, and the largest reserves of cobalt, uranium, platinum and diamonds.

However, several countries face high levels of poverty and inequality.

The meeting in Johannesburg is looking at the future of the African Growth and Opportunity Act (Agoa), a trade initiative passed in 2000 to deepen trade ties between the US and Africa.

It provides duty-free access to the US market and is due to expire in September 2025. African countries are pushing for an early 10-year extension, without changes, to reassure businesses and investors.

Elsewhere at the summit, US Secretary of State Antony Blinken said President Joe Biden's administration wanted to work with Congress to improve Agoa not just renew it without changes.