South Africa's business confidence improved in September, driven by robust tourism, higher precious metal prices and increased exports, data showed on Tuesday.

The South African Chamber of Commerce and Industry's (Sacci's) Business Confidence Index rose to 121.1 in September, up from 120.0 in August.

The business chamber releases the index every two months. August's business confidence level was also higher than a reading of 116.7 in July.

Economic activity and the financial environment showed more positive trends year-on-year, while month-on-month activity remained stable with some negative aspects, the South African Chamber of Commerce and Industry.

The chamber added that uncertainty was weighing on economic activity as South Africa tries to persuade President Donald Trump's administration to lower the 30% tariff imposed in August on its exports to the US.

"The trade tariff regime and the imposition of reciprocal tariffs have not yet entirely found their way into recent economic data," Sacci said in a statement.