JOHANNESBURG, July 23 (Xinhua) -- The relations between China and South Africa have become an exemplary model for South-South cooperation, Chinese Ambassador to South Africa Lin Songtian has said.

The diplomat made the remarks ahead of Chinese President Xi Jinping's upcoming state visit to South Africa, where Xi will also attend the 10th BRICS Summit in Johannesburg on July 25-27.

The trip is part of Xi's ongoing Middle East and Africa tour, which also includes the United Arab Emirates, Senegal, Rwanda and Mauritius. It is Xi's fourth visit to Africa as Chinese president.

"This year marks the 20th anniversary of the establishment of China-South Africa diplomatic ties, and the bilateral relations have grown into a comprehensive strategic partnership over the years," Lin said in a recent interview with Xinhua.

On economic and trade front, Lin said that China has been South Africa's largest trading partner for nine straight years, and South Africa is also China's largest trading partner in Africa. Bilateral trade amounted to over 39 billion U.S. dollars in 2017, more than 26 times the value back in 1998.

Lin said that Chinese investment in South Africa has exceeded 25 billion dollars. Noting that the South African government is championing the development of special economic zones, he encouraged Chinese companies to make more investment in this area.

So far, Chinese automaker FAW's South African plant has already been up and running, and a local factory of China's BAIC Group will roll out its first SUV soon.

The two countries have also achieved a lot in terms of mutual connectivity, Lin said, noting that direct flights are running between them and many Chinese commercial vessels have chosen South Africa's Cape of Good Hope as a transit point to Europe.

In the financial realm, China's major institutions have established branches or offices in Johannesburg, said the ambassador.

In people-to-people exchanges, South Africa hosts the largest number of Chinese students and Confucius Institutes in Africa, and the Chinese language has become part of the nation's educational curricula, Lin said.

He said Xi's upcoming trip will be the Chinese president's third state visit to South Africa, while South African President Cyril Ramaphosa will visit China and co-host the Beijing summit of the Forum on China-Africa Cooperation (FOCAC) in September.

"Frequent high-level visits are set to inject strong momentum into the development of bilateral relations," Lin said.

Lin said that BRICS, which groups Brazil, Russia, India, China and South Africa, has grown into an important force for global governance and a major engine for global economic growth.

"How BRICS nations strengthen their political mutual trust, unity and cooperation and how they make their own voices in safeguarding multilateralism will draw much attention during the Johannesburg summit," Lin said.