Chinese experts on Tuesday refuted claims by the Pentagon released in a report that China is developing cyberwarfare capabilities, saying that the U.S. military was attempting to blacken China's image.

"I've never heard about any plans by China to develop its cyber attack forces, not to mention China's so-called 'organized cyber intrusion," Hu Qiheng, president of the Internet Society of China (ISC) told Xinhua on the sidelines of the China Internet Conference, which opened?in Beijing on Tuesday.

"It is a mere fabrication that China is using computer technologies to intrude on other countries' sovereignty," Hu said.

The Chinese expert's comments came after the U.S. Department of Defense concluded early Tuesday in its annual assessment report sent to the U.S. Congress that "China is fielding...cyberwarfare capabilities to hold targets at risk throughout the region."

"The U.S. purpose (of releasing such a report) is to tarnish China's image and exaggerate the threat China poses," Hu said.

The U.S. was the top country of cyber attack origin in 2008, accounting for 25 percent of worldwide activity, according to a report by U.S. security firm Symantec.

The ISC said more than 1 million Internet Protocol addresses in China were controlled by overseas hackers while 42,000 Chinese websites were tampered or hacked in 2009.

Ni Feng, deputy director of the Institute of American Studies with the Chinese Academy of Social Sciences, said the United States has greatly outstripped any other country in terms of Internet technological power.

"As the source of Internet technology, the United States enjoys the most advanced Internet technologies and equipment in the world," Ni said, "thus it makes no sense and is beyond my comprehension for the United States to play up such cyber threat from China."

"Maybe the only reasonable explanation is that the United States has always been on the alert for China's development," Ni said. "The U.S. government needs this kind of rhetoric as an excuse to scale up its cyberwarfare capabilities and win support from Congress, the media and the public at large."

"If the United States continues such behavior, looking for topics to attack China, the mistrust between the two countries will only get worse," he added.