The boy picked by the Chinese authorities as the reincarnation of the Panchen Lama has visited Tibet's most sacred temple.
Norbu is not the Dalai Lama's choice
Gyaltsen Norbu was shown on Chinese state television being eagerly greeted by monks.
Norbu was named 11th Panchen Lama, second to the Dalai Lama in Tibetan Buddhism, after officials rejected the exiled Dalai Lama's own choice.
In Lhasa on Sunday the 15-year-old performed a number of rituals.
After placing a ceremonial cloth around a large statue of the founder of Buddhism, Norbu presented monks with red ribbons.
It is his third visit to the Himalayan capital and one of a handful of public appearances.
'Missing' Panchen Lama
In 1995, the Dalai Lama had named Gedhun Choekyi Nyima, then aged 6, as the true reincarnation of the Panchen Lama.
The Chinese authorities have not revealed his whereabouts but it is thought the boy is under house arrest.
Nyima's whereabouts are unknown
Deputy mayor of Lhasa Xiao Bai said on Saturday Nyima is "in good health and leading a normal and happy life".
"He's a senior in high school and his grades are quite good, but to avoid disrupting his and his family's life we have allowed no outside groups to meet him."
The Panchen Lama decides who will become Tibet's next Dalai Lama after the death of the incumbent, who is now in his late sixties.
The Beijing-designated Panchen Lama is always surrounded by bodyguards when he goes out in public.
Among his most recent public appearances was his opening of the
Communist Party Congress in Beijing in 2002.
The birth of Buddha was celebrated in Lhasa on Sunday
While in Lhasa, he met with Communist party officials and "200 representatives from all walks of life," the state Xinhua News Agency reported.
Taking control of Tibet in 1950, China has imposed communist rule in the mountain kingdom of 2.6 million inhabitants.
The Dalai Lama fled Tibet after a failed uprising against Chinese rule in 1959 and now lives in exile in India.