LONDON, July 21 (Reuter) - The Dalai Lama said on Sunday he was still optimistic he could persuade China to improve human rights in Tibet and to start negotiations with his government in exile but conceded he could not struggle on forever.

"Time is running out but I do not feel it is too late. Still there is hope," the 60-year-old Tibetan spiritual and political leader and 1989 Nobel Peace Prize winner told BBC television.

The Dalai Lama said he was optimistic because he felt that the leadership of China which annexed Tibet in 1950 -- was becoming more benign.

"I think China is much different than it was 30 or 40 years ago. Today's China has changed a great deal," said the Dalai Lama, who says the world needs to recognise that the survival of Tibetans as a distinct people is under threat from the Chinese.

Beijing has resettled large number of Chinese in Tibet and cracked down on any signs of support for independence, leading the Dalai Lama to accuse China of carrying out a policy of cultural genocide.

The Dalai Lama said he hoped that as political freedoms slowly increased, the Chinese living in Tibet would start to value local customs.

"When more liberty comes many of these Chinese will appreciate the Tibetan culture. So if the number of those Chinese who respect Tibetan culture is OK, then I think we can find some way to manage," he said.

"Our basic request is to please help us to get China to the negotiating table," said the Dalai Lama, who met Foreign Secretary Malcolm Rifkind and other officials during his visit to Britain.

The Dalai Lama, who now heads a government in exile based at the northern Indian town of Dharamsala, called on Beijing to lift strict visa restrictions on Tibet.

"If things are the way the Chinese present them, if they are very good, why not allow more people from outside especially journalists to go and see in every corner of Tibet?

"That's the proper way to show the world what they have really done, if there are good things there," he said.