Recent revelations about the National Security Agency spying on Germans has threatened to destabilize free trade talks between Europe and the United States.

According to a report by German newspaper Der Spiegel, the NSA collected more than half a billion calls, emails and SMS messages of German citizens since 2010.

It was also announced during the weekend that the NSA also monitored EU delegates in Washington and New York and hacked into their computer networks.

Spiegel claims to have seen official NSA slideshows and documents with the details of who was targeted, but the influential news magazine has neglected to publish the material online.

The justice commissioner of the EU, Viviane Reding, warned on Sunday that the deal to create a vast free trade zone could be jeopardized should the allegations prove to be true.

"There should be no spying between partners. We can't negotiate a large trans-Atlantic market if there is any doubt that our partners are bugging the offices of European negotiators," Reding said at a meeting with EU citizens in Luxembourg.

French President Francois Hollande offered the strongest response by an EU member nation by demanding a halt to the spying of European allies.

“We cannot accept this type of behavior between partners and allies. We demand that it ceases immediately,” Hollande said.

German Chancellor Angela Merkel compared it to Cold War tactics of the past and said that trust in Washington must be restored quickly. The free trade proposals would add 119 billion euros ($155 billion) to the European economy and 98 billion euros to the U.S., but more importantly it would create much needed jobs for both the U.S. and Europe.