BRASïLIA (AFP) - Brazil and Mexico have summoned US ambassadors to demand explanations over allegations that the National Security Agency spied on their presidents' communications.
Brazil's Foreign Minister Luis Figueiredo said the interception of Internet data from President Dilma Rousseff reported by US journalist Glenn Greenwald, if proven, "represents an unacceptable and unallowable violation of Brazilian sovereignty."
In Mexico, the foreign ministry said it sent a diplomatic note to Washington calling for an "exhaustive investigation" into claims that the NSA spied on President Enrique Pena Nieto before his election.
Mexico warned that, if true, the snooping would be a "violation of international rights."
A State Department official sought to downplay concerns saying that "while we are not going to comment publicly on every specific alleged intelligence activity, as a matter of policy we have made clear that the United States gathers foreign intelligence of the type gathered by all nations."
The claims reported by Mr Greenwald, who obtained secret files from NSA leaker Edward Snowden, follow allegations of widespread US electronic espionage in Latin America that angered the region's leaders.
The report emerged as Ms Rousseff and Mr Pena Nieto, who lead Latin America's two biggest economies, prepare to travel to Russia later this week for a Group of 20 summit during which they will see US President Barack Obama.
Ms Rousseff is also scheduled to visit Washington in October, five months after Mr Obama visited Mr Pena Nieto in Mexico.
Mr Greenwald, an American who lives in Rio de Janeiro and writes for Britain's Guardian newspaper, told Globo television that the NSA tracked Ms Rousseff's use of the Internet and accessed Mr Pena Nieto's emails before his election last year.
Figueiredo said he told US Ambassador Thomas Shannon that his government wanted "a formal, written explanation" this week.
After a cabinet meeting with Ms Rousseff, Justice Minister Jose Eduardo Cardozo said Brazil would wait for a response "and from there examine what measures to take."
"We are in an emergency situation due to these spying allegations," presidential secretary general Gilberto Carvalho was quoted as saying by O Estado de Sao Paulo newspaper.
The officials said Brazil wants Internet governance and US espionage accusations to be discussed in international forums.
The Mexican government later said it had summoned US Ambassador Earl Anthony Wayne but there was no immediate word on when the meeting would take place. A US embassy spokesman declined to comment.
In Brasilia, the Senate plans to name a special committee on Tuesday to investigate allegations of US spying in the South American country.
Senator Ricardo Ferraco, head of the Senate foreign relations committee, denounced the US government's "lack of limits."
Mr Greenwald told Globo on Sunday that a document dated June 2012 shows that the NSA was trying to better understand Ms Rousseff's methods of communication and interlocutors using a program to access all Internet content the president visited online.
The NSA program allegedly allows agents to access the entire communications network of the president and her staff, including telephone, Internet and social network exchanges.
The report also said the NSA intercepted some of Mr Pena Nieto's voicemails, which included messages in which he discussed the names of potential Cabinet members before his July 2012 election victory.
In July, Mr Greenwald co-wrote articles in O Globo newspaper revealing that the US government had a joint NSA-CIA base in Brazil to gather data on emails and calls flowing through the country.
The issue was discussed during a visit by US Secretary of State John Kerry in August, but Brazil said it was not satisfied by Washington's explanations.
Mr Cardozo, the justice minister, met with US Vice President Joe Biden in Washington last week to discuss the matter and said the United States rejected a Brazilian offer to negotiate a bilateral agreement on surveillance.
Snowden, a former NSA contractor wanted by Washington on espionage charges, is now a fugitive in Russia under temporary asylum.