US Ambassador to China Gary Locke, the first of Chinese descent in the position, delivered a public speech in Beijing on Wednesday and is set to leave the country on Saturday.

In the speech, Locke said he felt sad to leave China, but would leave with a sense of achievement and optimism for the Sino-US relationship,  the Phoenix TV reported Wednesday.

"China has a great future ahead of it," Locke told Chinese students at Beijing American Center on Wedndesday, but noted that reaching full potential will depend on "a neutral and respected judiciary, an active set of dedicated lawyers, wise leadership" and "reverence toward the rule of law."

Locke also called on China to have more tolerance for media criticism, saying "as a permanent member of the UN Security Council that has hosted the Olympics and sent a spacecraft to the moon, China should have the national self-confidence to withstand the media scrutiny."

China's foreign ministry spokeswoman Hua Chunying on Wednesday said that China is willing to talk and exchange ideas with other countries to make progress together on the basis of equality and mutual respect.

She said that China opposes any person using "so-called issues" as excuses to interfere with China's internal affairs and make thoughtless remarks.

Li Haidong, a professor with the Institute of International Relations at China Foreign Affairs University, told the Global Times that the relationship between China and the US has indeed moved forward during Locke's term as ambassador.

As the first Chinese-American to head the embassy in Beijing, Locke is quite different from his predecessors, said Li.

The US Embassy's pioneering in testing the air quality and PM2.5 has put both the embassy and the ambassador into the spotlight.

Li noted that it is inappropriate for a foreign embassy to criticize such issues. "But it did, to some extent, accelerate the public awareness over air quality."

Locke also attracted widespread attention in China with his Chinese-American background and his everyman image.

Locke was photographed carrying his own backpack and ordering his own coffee at an airport on his way to assume the envoy post two years ago, triggering a wave of public attention on the Internet.

"His behavior model is new and a good example of public diplomacy, which effectively promoted the US image in China," said Li.

Locke will leave the Chinese capital on Saturday and will be replaced by 72-year-old Senator Max Baucus.

"The appointment reflects that the US government attaches much importance to economic cooperation with China," said Li.

"After all, differences in economic cooperation are much easier to solve than those in politics," said Li, adding that both China and the US know economic cooperation will have bilateral benefits.