"Recently I had surgery on my knee, which has given me some problem," the exiled spiritual leader of Tibetan Buddhism said in a video message from the United States, where he is recuperating.
"However, I am recovering and have no problem at all now.
"There may be people trying to confuse you about my health, saying that the Dalai Lama has gone to a hospital and is undergoing treatments, and so on, making my condition sound grave.
"You don't need to trust such misinformation," he said.
The Dalai Lama received the Nobel Peace Prize from Egil Aarvik in Norway in 1989. (AP PHOTO)
A charismatic figure who popularised Buddhism internationally, the Dalai Lama won a Nobel Peace Prize in 1989 for keeping alive the Tibetan cause in exile.
He fled to India in 1959, nine years after China sent troops into the Himalayan region in 1950, saying it was liberating Tibetan "serfs".
As the spiritual leader ages and battles health problems, the appointment of his successor has become a looming issue for Tibetans struggling for more autonomy in China or outright independence.
Tibetan Buddhists believe that learned monastics are reincarnated after death as newborns.
The Dalai Lama has said he will clarify questions about succession - including whether and where he would be reincarnated - around his 90th birthday.
"I am nearly 90 now but I don't feel unhealthy, except for the slight discomfort in my legs," he said, adding that some issues are part of ageing.
"I would like to thank all my fellow Tibetans in and outside Tibet for your prayers on my birthday."
Tens of thousands of Buddhists and well-wishers around the world are gathering to celebrate and pray on Saturday for the long life of a leader who for them represents the strongest hope of an eventual return to Tibet.
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