U.S. Undersecretary of State for Economic Growth, Robert Hormats speaks at the 6th US-China Internet Industry forum in Beijing, China, Tuesday, April 9, 2013. Hacking that originates inside China is undermining its relationship with the United States and harms Beijing’s long-term interests, the top U.S. diplomat said Tuesday. (Ng Han Guan/AP)

At a rare public forum on cyberissues Tuesday featuring American and Chinese government officials, U.S. diplomats and business leaders tried using economic arguments to persuade China to stop its cyberattacks and Internet censorship.

China’s heavy-handed Web restrictions not only slow Internet speeds and make company data less secure, but they also have “tangible economic” effects on the country, said Gary Locke, the U.S. ambassador to China.

Undersecretary of State Robert Hormats was even more blunt in calling out China for its actions.

“I ask my Chinese friends to question whether this kind of activity serves China’s real interests as it seeks to attract high-end investment, aims to develop international markets for its innovative products, and wants its companies welcomed and respected as they increasingly invest around the world,” Hormats said.

In recent months, after news reports publicly tied cyber­attacks originating from China to the Chinese military, U.S. officials have taken a harsher and more direct tone in confronting China on the issue.

Tuesday’s comments were made during an Internet forum sponsored by Microsoft, which carefully featured an equal number of Chinese and U.S. officials.

Chinese officials stuck mostly to previous boilerplate responses to such accusations: China is in the early stages of its development; far from perpetrating cyberattacks, China is among the most frequent targets; andChina opposes the actions of rogue hackers.

One Chinese official, however, went on the offensive.

“Recently some people have cooked up this theory of a Chinese cybersecurity threat,” said Qian Xiaoqian, vice minister of China’s State Council Information Office. “It is a variation on the popular theory of a rising China threat.”

China has long opposed hacking, he said, and thinks “we shouldn’t militarize the cyberspace and attack other countries in violation of laws and regulations and also in violation of moral standards.”

In later comments, however, Qian seemed to agree that more could be done to create an environment welcoming to U.S. businesses. “The Chinese government should stick to the opening-up policy and further improve our legal framework and policies,” he said.

But longtime Microsoft executive Craig Mundie questioned whether the problem was a matter of policy or intent.

“A lot of this activity clearly originates in China, but is it the work of rogue actors or state actors?” he asked. Either way you cut it, he said, it suggests serious problems with China’s policies or with its enforcement of cybersecurity measures.