THE relationship between China and the United States is like a marriage, with both parties building trust and cooperation, visiting Vice Premier Wang Yang told the China-US Strategic and Economic Dialogue yesterday.

However, it is not like a gay marriage, Wang quipped as he sat next to US Treasury Secretary Jack Lew.

Both officials came to their positions this year and were co-chairing the annual meeting in Washington between the countries.

"In China when we say a pair of new people, we mean a newlywed couple," Wang said about himself and Lew. "Although US law does permit marriage between two men, I don't think this is what Jack or I actually want."

Wang went on to describe how the US and China must cooperate and build trust like a married couple, and respect each other's right to speak.

"(But) we cannot have a divorce the way Wendi and Rupert Murdoch just had," Wang said, referring to the high-profile divorce between the News Corp chief executive and his Chinese-born wife of 14 years, Wendi Deng.

"For that, it would be too big a price to pay," he said.

Wang became one of four vice premiers in March after serving as the Communist Party chief in Guangdong, one of China's richest provinces.

Wang said he was last in the US 10 years ago and wasn't sure how much had changed. "Well, in the past two days, I can see that the Americans are still taller than the Chinese and still have a stronger body and longer nose than the Chinese," he said.

A US official said: "Sometimes humor doesn't translate into a foreign language, but I thought he showed a good sense of humor."

Yesterday there was a round-table discussion among officials and Chinese and US business leaders. Washington wants Beijing to expedite economic reforms and reduce state-involvement in the economy; China has its concerns about the screening of companies wanting to invest in the US.

The most tangible outcome of Wednesday's talks were initiatives to reduce greenhouse gas emissions and air pollution. The two sides agreed to cooperate on cutting emissions from vehicles and coal combustion, and to promote more efficient use of energy in buildings, transport and industry.