European leaders are furious over new allegations that U.S. spy agencies monitored European Union diplomatic offices in Washington, New York, and Brussels.
It's the latest in a string of revelations by National Security Agency whistleblower Edward Snowden.
A report in Der Spiegel said the NSA monitored phone conversations and gained access to a computer network containing internal emails and documents of EU leaders.
European leaders are threatening economic sanctions and investigations.
The EU Justice Commission said "partners do not spy on each other."