The Dalai Lama says South Africa's failure to issue him a travel visa has forced him to call off his planned participation in this week's birthday celebration of anti-apartheid leader Desmond Tutu.

In a statement released Tuesday, the Dalai Lama's office in India said it is convinced that, “for whatever reason,” the South Africa government “finds it inconvenient” to issue a travel visa to the Tibetan leader.

The Dalai Lama requested a South African visa five months ago so he could attend Tutu's 80th birthday celebrations, which begins this Thursday.

South African officials have denied being under pressure from China, a key trading partner, to block the visit. China regularly applies diplomatic pressure to governments that permit visits by the Dalai Lama.

Beijing has often accused the Dalai Lama and his followers of advocating Tibetan secession, despite repeated assurances from the Buddhist leader that he only seeks to establish autonomy, rather than independence, for Tibet.

The Dalai Lama has visited South Africa three times in the past but his fourth visa application in 2009 was turned down.

Earlier this week, a joint statement by the Desmond Tutu Peace Center and the Office of Tibet in Pretoria said the South African government has been “profoundly disrespectful” to the Dalai Lama and Archbishop Tutu, both Nobel Peace Prize laureates.

South Africa's deputy vice president recently returned from a diplomatic visit to China, where authorities praised him for his country's “valuable support” on the Tibetan issue.