Tibet's government in exile has called on the international community to press China harder to address the grievances of Tibetans.
The appeal came amid a stepped up pace of self-immolations by Tibetans protesting Chinese rule in Tibet.
The self-immolation campaign began in February 2009 to protest what Tibetans say is Chinese repression of their culture. More than 100 people have set themselves on fire in Tibetan areas of China, and several more in other countries. A Tibetan man died after setting himself on fire in the Nepalese capital Kathmandu just Wednesday.
Beijing denies the charges of repression, and says the self-immolations are acts of terrorism.
Lobsang Sangay, head of the India-based Central Tibetan Administration, called on world governments and the United Nations Thursday to investigate the causes of the self-immolation campaign and work with China "to stop the deteriorating situation in Tibet."
Tibetan self-immolations since March 2011.
On Wednesday, sources inside China said the 100th person to self-immolate was 37-year-old Lobsang Namgyal, a monk formerly of the Kirti Monastery in Ngaba, or Aba in Chinese. He set himself alight on February 3 in a small town in Sichuan Province and died on the scene. Most of the self-immolators have died.
The self-immolation in Kathmandu was apparently timed to coincide with the important Tibetan New Year festival of Losar. Tibet's government in exile had asked Tibetans to show solidarity with Tibetans inside China by not celebrating the holiday.
More than 20,000 Tibetan exiles are living in Nepal, after a failed 1959 uprising against Chinese rule. Nepal has prohibited demonstrations by Tibetan exiles and cracked down on such gatherings in recent years, to avoid angering China.