BERLIN — Internet users worried about their personal information being intercepted by U.S. intelligence agencies should stop using websites that send data to the United States, Germany's top security official said Wednesday.

NSA leaker Edward Snowden claimed Google, Facebook and Microsoft were among several Internet companies to give the U.S. National Security Agency access to their users' data under a program known as PRISM. The companies have contested this, but the claims prompted outrage in Europe and calls for tighter international rules on data protection.

"Whoever fears their communication is being intercepted in any way should use services that don't go through American servers," German Interior Minister Hans-Peter Friedrich said.

He also said German officials are in touch with their U.S. counterparts "on all levels" and a delegation is scheduled to fly to Washington next week to discuss the claims that ordinary citizens — and even European diplomats — were being spied upon by the NSA.