Chinese President Xi Jinping on Thursday hailed visiting South African President Jacob Zuma as China's "good friend", months after the latter's government refused the Dalai Lama a visa.

"President Zuma is the Chinese people's old friend and good friend," Xi said as he welcomed Zuma on a state visit as trade and political ties between Pretoria and Beijing grow closer.

"South Africa is the comprehensive and strategic partner of China in Africa," said Xi, who visited South Africa in March 2013 as part of his first foreign trip as head of state.

"The two countries are equal, share mutual trust and cooperate on (a) wide range of sectors," he added. "We are good friends and good brothers that mutually benefit each other."

Zuma, who is accompanied by a high-profile delegation including ministers for the environment, international relations, trade and energy, transport and finance, responded by thanking Xi for his "warm hospitality" since arriving.

"For me, this is a manifestation of the friendship and solidarity that exists between the People's Republic of China and the Republic of South Africa," Zuma said.

China is South Africa's single largest trading partner, while South Africa is China's largest trading partner on the continent.

South Africa joined the BRICS bloc of developing economies with Brazil, Russia, India and China in 2011.

During the apartheid era, Zuma's African National Congress was supported by Moscow while Beijing backed the rival Pan Africanist Congress, but in recent years South Africa has maintained a strongly pro-China foreign policy.

In the last five years Pretoria has thrice declined a visa for the Dalai Lama, the exiled Tibetan spiritual leader and Nobel Peace Prize winner.

Dozens of Nobel laureates boycotted a September meeting in Cape Town following the latest refusal, which was widely regarded as a sign of South Africa's deference to Beijing.

Fellow laureate and anti-apartheid activist Desmond Tutu also slammed the government over the visa refusal. The meeting was forced to moved to Rome.

During Zuma's visit, China announced the signing of a series of agreements, including a memorandum of understanding on nuclear energy cooperation between China National Nuclear Corporation and the South African Nuclear Energy Corporation.

China said that the two sides agreed a five-to-10 year strategic programme on cooperation, as well as to improve bilateral cooperation in trade and investment between China's ministry of commerce and South Africa's department of trade and industry.

Detailed terms of the agreements were not immediately available.

South Africa said last month it had signed a nuclear energy cooperation agreement with China, calling the deal a "preparatory phase for a possible utilisation of Chinese nuclear technology". The deal followed similar agreements with Russia and France.

South Africa, which has one nuclear plant, is plagued by electricity blackouts and is seeking to reduce its heavy reliance on coal-fired power stations.

Electricity constraints have been blamed for limiting economic growth and productivity.

Zuma earlier held talks with Chinese Premier Li Keqiang, with Li congratulating Zuma on his re-election in May as South Africa's president.

"You have always attached high importance to South Africa's relations with China and you have made unrelenting efforts to grow China-South Africa relations," Li said.

"We have always appreciated our interaction between China and South Africa. I must say that we feel very much at home," Zuma responded.