France summoned the US ambassador Monday over newspaper claims that the US National Security Agency (NSA) spied on millions of phone calls in the country.
French Foreign Minister Laurent Fabius announced that he summoned the US ambassador to discuss the claims "immediately", reports BBC.
Interior Minister Manuel Valls said the allegations were "shocking", and added: "If an allied country spies on France, this is totally unacceptable."
Le Monde, a newspaper, says the data, based on leaks from Edward Snowden, a former intelligence analyst, suggest that the NSA monitored businesses and officials in France.
The paper says the NSA spied on 70.3 million phone calls in only 30 days between Dec 10, 2012, and Jan 8, 2013, in France. The agency also apparently captured millions of text messages.