He said: "If two people, a couple, really feel that way, it’s more practical, more satisfaction, and both sides fully agree, then okay!”
On whether same-sex marriage should be universally accepted, he said: "That’s up to the country’s law.”
And the Dalai Lama added that people should still follow their own religions’ rules on spirituality.
“People who have belief or who have special traditions, then you should follow according to your own tradition. Like Buddhism, there are different kinds of sexual misconduct, so you should follow properly.
“But then for a non-believer, that is up to them. So there are different forms of sex - so long (as it is) safe, okay, and (if both people) fully agree, okay,” he said.
He added that homophobia was “wrong.”
“It is a violation of human rights,” he said.
The Dalai Lama is Tibet’s exiled spiritual leader and won the Nobel Peace Prize in 1989.
His visit to the US saw him risk the wrath of China, who have named him an enemy of the state, who is determined to seek Tibetan independence.
The Dalai Lama has long denied these claims, saying that he wants only enough autonomy to protect Tibet's Buddhist culture.
The full interview will be aired on 10 March.
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