China has pledged $3.49-million to support HIV prevention services in South Africa over the next two years under a new partnership facilitated by UNAIDS, Beijing's ambassador said on Thursday.

South Africa, which has the world's largest population of people living with HIV, previously relied on the US for about 17% of its HIV budget - over $400-million a year - before Washington slashed foreign aid early this year.

Pretoria is now trying to plug the gap with domestic resources and support from other partners.

The Chinese grant will go towards HIV prevention services for young people and people who inject drugs as two of the groups at highest risk of HIV infection.

"We are honoured to deepen our longstanding partnership with South Africa through this grant to support the country's HIV response," Chinese Ambassador Wu Peng said in a statement ahead of the G20 leaders' summit in Johannesburg.

"In addition to this project, we stand ready to assist South Africa in establishing a sustainable HIV/AIDS response system through policy dialogue, innovative drug supply, technology transfer, and capacity building."

South African Health Minister Aaron Motsoaledi welcomed the support, saying it strengthened the country's HIV response.

The announcement follows a 2024 cooperation agreement between China's development agency and UNAIDS, the United Nations agency focusing on the longstanding HIV/AIDS pandemic.