But he urged both sides to take opportunities to form a closer relationship that will benefit both people and the world.
"China has a unique history, a unique culture, a unique philosophy, and we need to understand that difference. "Both people and both governments need to understand those differences if we are to be more successful in forging more collaborative and cooperative relationships," Locke said.
Locke arrived only a few days before US Vice-President Joe Biden's Aug 17-22 visit. Biden is expected to exchange views with Chinese leaders on issues such as South China Sea disputes, US arms sales to Taiwan and US debt.
Asked whether the US will continue to sell arms to Taiwan, which has long been a disrupting factor in China-US relations, Locke said US policy with respect to Taiwan was very clear and that will not change, without elaborating on it.
As a child of Chinese immigrants to the US, Locke is the first Chinese-American ambassador to represent the US in the land of his ancestors.
Even before arriving in Beijing, photos appeared online of Locke queuing at a Seattle airport coffee shop trying to use a coupon without security guards and secretaries.
Asked about the pictures, and whether he would take to China's Internet to talk directly to users, Locke said: "We look forward to using all forms of communication, including blogging and the electronic media, to spread the word about our mission here in China."
Shen Dingli, a professor at the Institute of International Studies affiliated to the Shanghai-based Fudan University, said Locke must work hard to prevent relations from retrogressing following US arms sales to Taiwan and Obama's meeting with the Dalai Lama, as well as trade friction.
Shen said it will not be an easy job for Locke.
He also suggested that Locke would take a more confrontational stance than his predecessor to show that his Chinese origins do not make him appear more pro-China, as some have predicted might happen.
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