Thabo Masebe, a presidential spokesman, said on Tuesday that a visit to South Africa by the Dalai Lama was not welcome while the country is trying to boost its standing on the world stage.
"You can't remove Tibet from [the Dalai Lama]," he said. "That becomes the issue and South Africa is no longer the issue."
The postponement of the conference comes after several laureates, including Desmond Tutu, a South African archbishop, pulled out in protest at the refusal to grant the Dalai Lama entry to South Africa.
The South African newspaper Sunday Independent said the refusal to allow the Dalai Lama into the country was due to pressure from China, a major trading partner for South Africa.
The newspaper said the Chinese embassy in South Africa had confirmed that Beijing had warned the South African government that allowing the Dalai Lama into the country would harm bilateral relations.
China said it would continue to oppose the Tibetan spirituals trips to other countries as well.
Qin Gang, China's foreign ministry spokesman, said China "resolutely opposes any country's government having official contact with the Dalai Lama or enabling or offering a platform for his splittist activities."
"We also resolutely oppose any foreign country using the Tibet issue to interfere in China's internal affairs," he said.
More than 50 years have passed since the Dalai Lama escaped into exile in India after Chinese troops crushed a Tibetan uprising.
China claims Tibet as part of its territory, but many Tibetans say Chinese rule deprives them of religious freedom and autonomy.
Meanwhile, Beijing accuses the Dalai Lama of pushing for Tibetan independence and fuelling anti-Chinese protests.
The Dalai Lama has said that he is seeking increased autonomy for Tibet from Beijing rather than outright independence.