Peter Hustinx, director of European Data Protection, said regional computer infrastructure needs a robust cybersecurity policy in the digital age but privacy is just as important.
"There is no security without privacy," he said in a statement from Brussels.
Internet and mobile phone service providers acknowledged they were cooperating with U.S. national security officials on gathering information from consumers. Details of the surveillance program known as "Prism" were leaked to a British newspaper by Edward Snowden, 29, a former Booz Allen Hamilton contractor working with the U.S. National Security Agency.
Hustinx said tackling cybersecurity challenges internationally was something that required widespread cooperation and trust.
"If the European Union wants to cooperate with other countries, including the USA, on cybersecurity, it must necessarily be on the basis of mutual trust and respect for fundamental rights, a foundation which currently appears compromised," he said.
The European Parliament said last week most of its members "roundly condemned" the U.S. surveillance program, but said broad security cooperation with the United States was a top priority for the bloc.
Prism extended into the European community.