The leaders of South Africa and the Democratic Republic of Congo have signed nearly 40 trade agreements including one to revive a hydroelectric scheme.
The Grand Inga Dam project is a series of seven proposed hydroelectric power stations across the Congo river.
If built as planned, it would be the largest of its kind in the world.
South African President Cyril Ramaphosa signed the agreements with his counterpart Felix Tshisekedi in the Congolese capital, Kinshasa.
South Africa is experiencing a massive electricity crisis with frequent power cuts.