Tibet's "prime minister in exile" Lobsang Sangay on Monday described his complete surprise when the Dalai Lama last year handed him responsibility for the movement's political future.

The Dalai Lama, the spiritual leader of Tibetan Buddhism, announced in March 2011 that he was retiring from political duties and upgrading the role of prime minister shortly before elections that were won by Harvard-educated Sangay.

The decision shocked many Tibetans, who see the Dalai Lama as the figurehead for the struggle against what they say is Chinese repression in their homeland, but the Nobel laureate said he wanted more democracy in the exiled community.

Sangay, 44, who has never been to Tibet, is now based in the northern Indian hilltown of Dharamshala where many Tibetans have lived since the Dalai Lama fled Tibet after a failed uprising in 1959.

"When I ran for the election I always thought I was coming to Dharamshala to serve the Tibetan people, and work under the Dalai Lama," Sangay told reporters in New Delhi.

"But I never thought that he would give us the surprise by saying 'you are on your own -- take all the political authority I have, and fill in the shoes and lead the Tibetan movement forward'.

"It is one of the most difficult jobs in the world."

Since taking up the role in August 2011 Sangay has faced a major challenge over the scores of people who have set themselves alight in protests in Tibetan-inhabited areas of China.

On Monday, he repeated his appeal for Tibetans inside China not to set themselves on fire, but said the often fatal protests were a reflection of Chinese government policies.

"Since I took over, the situation in Tibet became worse... and given the constraints on any freedom of speech, Tibetans have unfortunately resorted to self-immolation," he said, adding 40 of 49 protests had resulted in death.

"We have made several appeals to Tibetan people not to resort to drastic actions like self-immolation but it continues today. It brings sadness to Tibetan people and as Buddhists we pray for them."

China blames the Dalai Lama for inciting the protests in a bid to split Tibet from the rest of the nation and insists Tibetans now have better lives due to Chinese investment.

The position of prime minister in exile was a low-profile role before the Dalai Lama, now 77, devolved power in an attempt to lessen his own totemic status and secure the movement's future after his death.

Sangay, who supports autonomy for Tibet within China rather than outright independence, has travelled widely since he was sworn in one year ago, though the Dalai Lama remains the universally recognised face of the movement.

"The Dalai Lama is a global statesman... a global phenomenon and is highly respected and revered by Tibetans and people around the world, so there is no way a single person can fill in his shoes," Sangay said.

He added that instead he was doing his "best to fulfil the Dalai Lama's vision to strengthen and sustain the non-violent, democratic system we have so we can carry forward the Tibetan movement for another 50 years if need be."

Sangay said an equivalent to the Arab Spring uprisings had been going on in Tibet for decades and called for an international delegation to be sent to China to investigate the causes behind the fire protests.