The Dalai Lama [Images] has ruled out any more "concessions" to China on Tibet [Images] and threatened to resign as leader of Tibet's exiled government if violence in his Himalayan homeland went "out of control."

"If violence becomes out of control then my only option is to resign," the exiled Tibetan spiritual leader told reporters on the sidelines of a five-day conference on compassion in Seattle.

"If the majority of people commit violence, then I resign," the 72-year-old Nobel Peace Prize Laureate said on his first visit to the United States since the recent Chinese crackdown on dissent in Tibet.

The Dalai Lama said he was fully committed to his "middle way" approach to Tibet's relationship with China. "I am fully committed to middle approach; further more concessions, I don't know," he said.

"Our struggle is with a few in the leadership of the People's Republic of China and not with the Chinese people," the Dalai Lama said in a statement.

However, he expressed fears that suppression in Tibet may increase if the present situation continues.

"I am very much concerned that the Chinese government will unleash more force and increase the suppression of the Tibetan people," he said.

The Dalai Lama also said his representatives were holding "private talks" with Beijing [Images] following the eruption of protests in Tibet last month against the Chinese rule.

Describing the talks as "some efforts" through "private channels", the Dalai Lama said, the talks were "still in full mystery. I don't want any speculation," the Seattle Times reported.

However, he said he himself had no direct contact.

The Dalai Lama said he supported the Beijing Olympics [Images] and was saddened by recent anti-Chinese protests that marred the traditional torch relay through the streets of London [Images], Paris and San Francisco.

"Everyone knows I support Olympic Games," he said, declining to say whether he believed world leaders should attend the opening ceremony scheduled for August 8.

"That is, I really feel, up to the individual," he said. "My own case, I don't think I will get an invitation. If some invitation comes, then the situation -- the most important question is not a question of invitation, it is the situation inside Tibet," he said.

The Dalai Lama, who has lived in exile in India since a failed uprising against Chinese rule in 1959, has threatened to step down in the event of sustained violence in Tibet.

The Tibetan capital Lhasa witnessed the biggest protests in 20 years last month. The riots then spread to neighbouring provinces inhabited by Tibetans.

Beijing has accused the Dalai Lama of "masterminding" the unrest and of seeking to split Tibet from China and said the violence in Tibet was part of a bid for independence and to ruin the upcoming Olympic Games in Beijing.

During the weekend, Chinese President Hu Jintao defended the crackdown in Tibet and rubbished the claims that the riots in Lhasa were linked to human rights.

"Our conflict with the Dalai clique is not an ethnic problem, not a religious problem, nor a human rights problem," Hu told Australian Prime Minister Kevin Rudd.

Tibetan exiles say more than 150 Tibetans were killed in China's crackdown on the protests against its rule.

Beijing says Tibetan "rioters" have killed 20 people.

The Dalai Lama has also urged the Chinese government to "open (Tibet) to the world," with visitors and media allowed to go there freely to "see the actual situation."