Mexico's leader said Thursday US President Barack Obama promised an investigation into allegations the National Security Agency spied on him, and that he asked Obama to punish those responsible if laws were broken.
"The Mexican government has made it clear that there must be an investigation and that there must be sanctions if there were acts that were outside international agreements and outside the law," President Enrique Pena Nieto said after speaking with Obama by telephone.
"I received from President Obama a commitment that this investigation will take place," he told Russia's RT television on the sidelines of a Group of 20 summit in Saint Petersburg that the two leaders are attending.
Their conversation came four days after US journalist Glenn Greenwald, who has access to documents leaked by former NSA contractor Edward Snowden, reported that the spy agency hacked Pena Nieto's emails before his election last year.
Greenwald also told Brazil's Globo television that the NSA had monitored the online activities of President Dilma Rousseff, who is also attending the G20 meeting.
The allegations have put in doubt Rousseff's visit to Washington on October 23. Officials said Thursday that a trip Saturday by a Brazilian delegation to prepare her visit was cancelled.
Brazil and Mexico have summoned the US ambassadors to their respective countries to demand an explanation about the allegations.
Pena Nieto had said Wednesday that he would seek to raise the issue with Obama at the G20 summit.
The new claims of spying in Latin America came two months after allegations of widespread US electronic espionage in the region that infuriated allies and rivals alike.
In his latest report, Greenwald said the NSA intercepted some of Pena Nieto's phone calls, text messages and emails, including communications in which he discussed potential cabinet members before he was elected in July 2012.