Washington is under fire from key allies after reports the United States spied on their leaders' communications.
The reports are the latest allegations to emerge from fugitive contractor Edward Snowden about a huge US spy programme run by the National Security Agency (NSA).
These are the foreign leaders reportedly targeted:
- ANGELA MERKEL: German Chancellor Merkel's mobile phone might have been tapped by the NSA and she has spoken with US President Barack Obama about it, a German government statement said late Wednesday.
If such practices took place, Merkel made it clear she "regards them as completely unacceptable," her spokesman Steffen Seibert said in a statement.
Merkel demanded answers after learning the NSA might have monitored her phone and warned that would represent a "breach of trust" between international partners.
White House spokesman Jay Carney told media: "The president assured the chancellor the United States is not monitoring and will not monitor the communications of the chancellor."
He did not speak about past activities however, and the German foreign ministry summoned US Ambassador John B. Emerson on Thursday in relation to the affair.
- DILMA ROUSSEF: Brazilian President Dilma Roussef sharply criticised the US after the daily O Globo reported in September that the NSA had intercepted some of her e-mails and telephone calls, along with those of close aides.
Roussef cancelled a planned visit to the US, but later addressed the United Nations General Assembly in New York and called the spy programme "an affront to the principles...that otherwise govern relations between countries."
On October 15, Brazil said it will activate a secure email system in November to protect government communications from spying by the United States and other countries.
- PENA NIETO/CALDERON/FOX: Mexican President Enrique Pena Nieto, who took power in December, has ordered an "exhaustive" probe into reports that the NSA hacked his emails while he was a candidate last year, as well as the messages of predecessor Felipe Calderon while in office.
The Mexican investigation will look into whether such spying indeed took place and if any local officials were complicit, Interior Minister Miguel Angel Osorio Chong said.
The allegations that Calderon was spied on from May 2010 were reported by German weekly Der Spiegel after a similar report by US journalist Glenn Greenwald last month that Pena Nieto had been targeted by the NSA.
On September 5, Pena Nieto said that Obama promised an investigation into the allegations.
Former Mexican president Vicente Fox said that "of course" he was spied on when he was in power between 2000-2006.
Fox told MVS Radio in Madrid on Wednesday: "It's nothing new that there's espionage in every government in the world, including Mexico. I don't understand the scandal."
In addition, British daily the Guardian said on June 17 that the British authorities had spied on delegates from the Group of 20 richest countries during two meetings in Britain in 2009. According to a secret document from the NSA provided by Snowden, and quoted by the newspaper, the US profited from this to try to listen to the satellite calls to Moscow by the Russian president at the time, Dmitry Medvedev.