The United States monitored 70.3 million phone calls in France over a 30 day period starting Dec. 10 until Jan. 8.
French newspaper Le Monde reported the news on Monday after looking through the leaked Edward Snowden documents, BBC News reports. The calls were monitored because of certain key words used in the various conversations from more than just terrorist suspects.
Prime Minister Jean-Marc Ayrault said, "It's incredible that an allied country like the United States at this point goes as far as spying on private communications that have no strategic justification, no justification on the basis of national defence."
The phone calls, and text messages, were intercepted as part of an operation named US-985D. Le Monde did not mention if it was still ongoing or if any information from the text and calls had been saved.
French diplomats were not pleased with the report and had U.S. Ambassador Charles Rivkin meet at the French Foreign Ministry, according to CNN.
French Foreign Minister Laurent Fabius told reporters in Luxembourg, "These kinds of practices between partners, that violate privacy, are totally unacceptable." He added, "We must quickly assure that these practices aren't repeated."
U.S. Secretary of State John Kerry plans to see Fabius on Tuesday as he will already be in Paris for another meeting.
Le Monde's report dropped just a day after Der Spiegel reported that the National Security Agency also listened in on Mexican government communication, including hacking former President Felipe Calderon's email.