France and Mexico have angrily demanded prompt explanations from Washington following fresh, "shocking" spying allegations leaked by former US security contractor Edward Snowden.

France summoned the US ambassador on Monday to protest allegations in Le Monde newspaper about large-scale spying on French citizens by the US National Security Agency.

The reports in Le Monde and German weekly Der Spiegel revealed that the NSA secretly recorded tens of millions of phone calls in France and hacked into former Mexican president Felipe Calderon's e-mail account.

French Interior Minister Manuel Valls described the revelations in Le Monde as "shocking", in an interview on Monday with Europe 1 radio.

The spy agency taped 70.3 million phone calls in France over a 30-day period between Dec 10 and Jan 8 this year, Le Monde reported in its online version, citing documents from Snowden.

According to the paper, the NSA automatically picked up communications from certain phone numbers in France and recorded text messages under a program code-named "US-985D".

Le Monde said the documents gave grounds to believe the NSA targeted not only people suspected of being involved in terrorism but also high-profile individuals from the world of business or politics.

Valls said the revelations would call for "precise explanations by US authorities in the coming hours".

US authorities declined comment to the French daily on the "classified" documents.

The Le Monde article followed similar revelations by Der Spiegel - also based on documents provided by Snowden - that US agents had hacked into the Mexican presidency's network, gaining access to Calderon's account. Snowden's leaked information has prompted angry recriminations against Washington in Latin America, particularly Brazil, according to Der Spiegel.

According to the Le Monde report, the NSA said the information contained "diplomatic, economic and leadership communications which continue to provide insight into Mexico's political system and internal stability".

The agency reportedly said the president's office was now "a lucrative source".

Mexican authorities said they would be seeking answers from US officials "as soon as possible" following the allegations.

"The Mexican government reiterates its categorical condemnation of the violation of privacy of institutional communications and Mexican citizens," Mexico's Foreign Ministry said in a statement on Sunday.

"This practice is unacceptable, illegal and against Mexican and international law," the statement read.

Snowden, who has taken refuge in Russia, is wanted in the United States for espionage and other charges after leaking details of the NSA's worldwide snooping activities, which triggered a global furor when published in major newspapers in June.

AFP-Reuters