Nangsa Choedon, the Dalai Lama's spokesperson, told AFP that the South African government "conveyed by phone to me they will not be able to grant the visa for the reason that it would disturb relations between China and South Africa".
"For now the Dalai Lama has decided to cancel his trip to South Africa," said Choedon, South African news website IOL reports.
The annual Nobel summit is attended by Nobel Peace Laureates, leaders and other organisations from around the world. This year, the summit will take place from October 13 to 15 in Cape Town.
This is not the first time that South Africa has refused to grant the Dalai Lama a visa. He has had to cancel engagements in the country three times in five years after failing to secure a visa.
According to IOL, the other Nobel Peace Laureates have reportedly told Archbishop Desmond Tutu, one of South Africa's four Nobel winners (the other three being Nelson Mandela, FW de Klerk and Albert Luthuli), that they will boycott the summit if the Dalai Lama is not allowed to enter the country.