The National Security Agency recorded 70.3 million French civilian telephone conversations from Dec. 10, 2012, to Jan. 8 of this year, French newspaper Le Monde reported Monday.
The agency also intercepted communications of the Mexican government for years, has read text messages and listened to phone calls of President Enrique Pena Nieto and has hacked into the email servers of private companies in Latin America, according to a report published on Sunday by Der Spiegel, a German newspaper.
Both reports are based on documents leaked by former NSA contractor Edward Snowden, who is in Russia evading U.S. persecution for revealing classified information from the NSA.
The news is the latest in a long line of revelations about the secretive agency. Previous document releases revealed that the agency intercepts and monitors the communications of U.S. citizens without warrants and conducts surveillance on several other countries, including U.S. allies.
Le Monde's report emerged as U.S. Secretary of State John Kerry arrived in Paris for diplomatic talks about a peace process for Israel and the Palestinian territories. The U.S. ambassador to France has been summoned to the French foreign ministry to discuss the newspaper's allegations.
Mexico's foreign ministry condemned "the violation of privacy of institutional communications and Mexican citizens," according to a statement released Sunday. "This practice is unacceptable, illegitimate and contrary to Mexican law and international law."
The documents obtained by Der Spiegel show that in May 2010 the NSA was able to hack into an email server used by the Mexican government and gain access to then-president Felipe Calderon's public email account, along with the accounts of his cabinet members.
The NSA documents called the server a "lucrative source" of information because it allowed the U.S. to see "diplomatic, economic and leadership communications which continue to provide insight into Mexico's political system and internal stability," according to Der Spiegel.
Der Spiegel's report shows that the NSA rated information targets on a scale from 1 to 5, with 1 the highest priority for interception. Information about Mexico's ongoing drug war was rated 1, while information about Mexico's economic stability, human-rights record, trade relations and military capability were rated 3, according to the paper.
The U.S. monitored not only high-ranking officials but also those they thought might come to power, according to the report.
For two weeks in May 2012, the NSA intercepted phone calls and 85,489 text messages from then–presidential candidate Pena Nieto and his close associates, according to Der Spiegel.
The new documents bring into question how much of the NSA's work was done in the name of security and how much was done for the sake of furthering U.S. economic and diplomatic interests.
According to the Der Spiegel report, the NSA was able to procure internal documents that were funneled into 260 classified U.S. reports. Those reports were used to prepare politicians for talks on political issues as well as to plan international investments.
The documents say those efforts were a "tremendous success" and "just the beginning" of a longer-term plan to survey the Mexican government.
The revelations are likely to strain U.S. relations with Mexico and other Latin American countries, some of which expressed displeasure with earlier document leaks that showed the U.S. spied on Latin American citizens and politicians.
Brazilian President Dilma Rousseff has been one of the most vocal critics of the NSA. She has accused the agency of using surveillance to gain an economic advantage over countries.
At the U.N. General Assembly last month, Rousseff hinted at her anger with the U.S. for its spying activities.
"The right to safety of citizens of one country can never be guaranteed by violating fundamental human rights of citizens of another country," she said, never mentioning the U.S. or the NSA by name.
Brazil plans to introduce a law that would require companies like Facebook and Google to store Brazilian customers' data within Brazil in order to subject them to Brazilian data-privacy laws and protect its citizens against U.S. hacking.
Other Latin American leaders have also chastised the U.S. for spying, including Bolivia's President Evo Morales and Venezuela's President Nicolas Maduro, who both offered asylum to Edward Snowden.