The EU said Tuesday it will seek a strong commitment from the United States to respect the rights of European citizens, following revelations that Washington is running a worldwide Internet surveillance programme.

Viviane Reding, the EU's Justice Commissioner, "will raise the issue with force and determination" at a meeting in Dublin on Friday with US officials, the bloc's Health Commissioner Tonio Borg said.

"The commission is asking for clear commitments from the United States as to the respect of the fundamental right of EU citizens to data protection," Borg said in a statement to the European Parliament in Strasbourg, France.

The US spy programmes, revealed by The Guardian and Washington Post newspapers, "potentially endanger the fundamental right of privacy and the data protection of EU citizens," Borg said.

"Vice president Reding will raise this issue with force and determination at the upcoming EU-US ministerial on Friday in Dublin," he said.

The EU "will request clarifications as to whether access to personal data within the framework of the PRISM programme is limited to individual cases and based on concrete suspicions, or if it allows bulk transfers of data," said Borg.

Under the so-called PRISM programme, America's National Security Agency can issue directives to Internet firms like Google or Facebook to win access to emails, online chats, pictures, files and videos that have been uploaded by foreign users.

The programme was revealed by whistleblower Edward Snowden, a 29-year-old technology expert working for a private firm subcontracted to the NSA.

US President Barack Obama has defended the spy programmes as a "modest encroachment" on privacy, needed to keep Americans safe from terrorism.