BRUSSELS - The EU has warned President Barack Obama’s administration of “grave adverse consequences” to the rights of European citizens from a huge US Internet surveillance programme, officials said Wednesday.

Viviane Reding, the EU’s Justice Commissioner, wrote a letter on Monday to US Attorney General Eric Holder demanding “swift and concrete” answers about the spy scheme when they meet in Dublin on Friday. She set out seven detailed questions about the PRISM spy programme, which were leaked by whistleblower Edward Snowden and revealed by The Guardian and Washington Post newspapers last week.

“Programmes such as PRISM and the laws on the basis of which such programmes are authorised could have grave adverse consequences for the fundamental rights of EU citizens,” she wrote.

Her questions to Holder include whether EU citizens were targeted by the US programmes, whether Europeans would be able find out whether their data has been accessed, and whether they would be treated similarly to US nationals in such cases. Reding said that “given the gravity of the situation” she expected “swift and concrete answers to these questions” at her meeting with Holder. The EU official also warned that the European Parliament “is likely to assess the overall transatlantic relationship also in the light of your responses”. Obama has defended the spy programmes as a “modest encroachment” on privacy that are needed to keep Americans safe from terrorism.

Meanwhile, bombshell revelations about the United States’ wide-reaching surveillance programmes could spur China and other countries to expand their own efforts, Beijing-based dissident Ai Weiwei warned on Wednesday.

America’s huge dragnet of Internet and phone data, exposed in recent days through leaks and reports, has triggered a heated debate about privacy and national security.

Chinese social media users have made comparisons to their own government, which conducts extensive domestic surveillance and faces mounting accusations of aggressive cyber-spying abroad.

The high-profile outspoken artist said America’s behaviour was especially worrying because the country played a leading role in setting Internet norms.

“The US has the edge in technology. It’s a leader. Many of the rules about information the ethics, the laws, will be set by these leading countries,” Ai told AFP.

“Other countries will at least refer to them or even match them.”

While the US government faced more limits, he said, both countries were violating citizens’ privacy in the name of national security.

“They face different types of restrictions, whether cultural or systematic... but when it comes to invading citizens’ privacy there is no difference.”

He added that the extent of both countries’ surveillance was difficult to compare since much remained unknown.

The leaks and reports have revealed that US government bodies are tapping the servers of nine Internet giants including Apple, Facebook and Google, and collecting a vast sweep of phone records.

The IT contractor behind the Internet surveillance leaks, Edward Snowden, gave an interview in Hong Kong soon after the story first broke.

A Chinese foreign ministry official in the semi-autonomous city was quoted in Chinese media as saying on Tuesday that Beijing had not received a request from the US regarding Snowden.

“Not yet,” the ministry’s commissioner in Hong Kong, Song Zhe, said in response to questions from the Oriental Daily.

Beijing has legal authority to handle defence and foreign affairs in Hong Kong.

Users of China’s popular Twitter-like service Sina Weibo offered mixed views.

“Terrorism is pushing the US to quietly centralise more and more power,” said one.

Another gave America credit for acknowledging its activities after they had been exposed, saying: “Some countries that monitor the phones of their people are not brave enough to admit it.”

China’s state-run media has said little of the matter.

Ai surmised: “They do the same thing themselves, so there’s not much to say.”