"There is a tremendous opportunity here to craft something that is a win-win for both sides," said Florizelle Liser, head of the US negotiating team.
"What we achieve here could become a model for US global negotiations and serve as an example of what we can do with other developing countries," she said.
The negotiations with the Sacu countries - South Africa, Botswana, Lesotho, Namibia and Swaziland - are the first between the United States and sub-Sahara Africa, Liser said.
"Southern Africa is the largest beneficiary of the Africa Growth and Opportunity Act (US legislation giving favourable market access to certain African countries).
"If these countries can achieve guaranteed access to the largest market in the world it will greatly increase their attractiveness to investors," she said.
South Africa's deputy director general of trade and industry, Tshediso Matona, said the free-trade agreement South Africa reached with the European Union in 2000 served as a standard for the negotiations with the United States. The first round of talks in Pretoria started Monday and will end on Friday.
"These negotiations with the US will be difficult. A basic agreement is attainable in 18 months. The US has a template to work on in respect of the agreements it concluded with Singapore and Chile," said Matona.
"Ratification of the agreement with Chile was delayed because of Chile's stance on the US war on Iraq. We feared this might also happen to us, but here we are."