People surf the Internet in Jinan, in eastern China's Shandong province. The United States ramped up pressure on China to drop a new requirement for all computers to carry Internet filtering software, fearing it was a means for censorship.

The United States ramped up pressure on China to drop a new requirement for all computers to carry Internet filtering software, fearing it was a means for censorship.

Commerce Secretary Gary Locke and US Trade Representative Ron Kirk said China may be violating World Trade Organization obligations by requiring that all computers sold in the country from July 1 have the "Green Dam" program.

"China is putting companies in an untenable position by requiring them, with virtually no public notice, to pre-install software that appears to have broad-based censorship implications and network security issues," Locke said.

Locke and Kirk said they sent joint letters to their counterparts at China's Ministry of Industry and Information Technology and the Ministry of Commerce.

Beijing says the Chinese-made Green Dam software will filter out pornography, protecting young people within the world's largest online population.

But trade and rights groups fear that Green Dam is another attempt by China to control access to the Internet.

China has a history of blocking access to sites carrying politically sensitive topics such as the 1989 Tiananmen crackdown on democracy protesters and the banned Falun Gong spiritual movement.

"Protecting children from inappropriate content is a legitimate objective, but this is an inappropriate means and is likely to have a broader scope," Kirk said in a statement.

The United States ramped up pressure on China to drop a new requirement for all computers to carry Internet filtering software. Commerce Secretary Gary Locke and US Trade Representative Ron Kirk said China may be violating World Trade Organization obligations with its rule that all computers sold in the country have the "Green Dam" program.

"Mandating technically flawed Green Dam software and denying manufacturers and consumers freedom to select filtering software is an unnecessary and unjustified means to achieve that objective, and poses a serious barrier to trade," Kirk said.

An association representing US computer makers hailed President Barack Obama's administration for the intervention, saying Washington had previously shown tepid support for them when they faced pressure abroad to limit freedoms.

Ed Black, head of the Computer & Communications Industry Association, called the letter "a good initial step."

"It signals Internet freedom will be an increasingly important issue for this administration," he said in a statement.

"We hope the Chinese will reconsider and not demand tools to easily expand Internet censorship and spying on Chinese citizens," he said. "But the problem is not just with the Chinese. It?s a global issue."

The row over the Chinese software comes as technology takes an emblematic role in the protests in Iran, where critics of the clerical regime have turned to microblogging site Twitter, Facebook and other social networking sites to mobilize.

The US government, while pledging not to intervene in Iran, spoke with Twitter about delaying scheduled maintenance to its site.

US embassy officials met Chinese authorities last week to voice "concern" about the software, without publicly demanding that Beijing drop the rule.

But Chinese state media said Tuesday that Beijing would not back away from the new rule.

Earlier this month, the state-run Liberation Daily newspaper said that China was trying to protect young people among the country's 300 million Internet users.

"The state encourages research into Internet products that help minors surf the web in a healthy manner," it said.

Questions have also been raised about the Internet software's security vulnerabilities.

Researchers at the University of Michigan who examined the software have said it contained serious security vulnerabilities that could allow outside parties to take control of computers running it via remote access.

© 2009 AFP