Speaking to 200 members of both Houses of Parliament, the Tibetan leader said he wanted talks on the future of Tibet and called for "urgent intervention and action" by the international community to secure them.
China had earlier warned that the decision to allow the Dalai Lama to address peers and MPs would have an adverse effect on Sino-British relations.
The Tibetan leader admitted the delicate negotiations over Hong Kong made it more difficult for Britain to exert pressure. But he said: "The reality today is that Tibet is an occupied country under colonial rule. This is the essential issue which must be addressed and resolved through negotiations.
"Tibet - an ancient nation with a unique culture and civilisation - is disappearing fast. In endeavouring to protect my nation from this catastrophe, I have always sought to be guided by realism, moderation and patience.
"However, it has now become clear that our efforts alone are not sufficient to bring the Chinese government to the negotiating table."
The best way of solving conflict was through dialogue, he said. "As soon as some positive indication comes from the Chinese side, I'm ready to talk."
The Dalai Lama has been the political as well as the spiritual leader since China invaded Tibet in 1950. He has lived in exile since 1959 while fellow countrymen who remained have suffered repression and political persecution under Chinese rule.
The week-long visit by the Dalai Lama, his eighth to Britain, follows a successful visit to Germany last month after which the Bonn parliament backed a resolution condemning China's human rights record in Tibet. China retaliated by cancelling visits by senior leaders, jeopardising trading links.
In Britain, an intense lobbying campaign secured him a meeting yesterday with Robin Cook, Labour's foreign affairs spokesman, and he is due to meet Malcolm Rifkind, the Foreign Secretary, today.
Cui Tiankai, a Chinese foreign ministry spokesman, said: "By inviting the Dalai Lama to visit Britain and offering him a forum, the Tibetan group of the British House of Commons abets the Dalai's action to split the motherland. It will bring about adverse effects to the Sino-British relations."
But the visit was thought unlikely to develop into a diplomatic crisis.
Yesterday, the Dalai Lama repeated his assertion that he was not seeking full independence for Tibet at present but wanted a compromise that restored the rights of his people.
He dismissed allegations from British Buddhists that he was persecuting his own people. The New Kadampa Tradition claims he sent security forces into Tibetan refugee settlements in India to root out worshippers of a deity, Dorje Shugden. His British opponents have threatened to demonstrate against him.
The Dalai Lama urged journalists to go to India to check for themselves. He added that the Dorje Shugden deity "degenerates an essential part of Buddhism".Reuse content