Latin American nations from Mexico down to Argentina are demanding answers from the United States after a report of vast US spying on close allies and critics alike.
Governments voiced a mix of outrage and concern after the Brazilian newspaper Globo citing documents leaked by fugitive US intelligence whistleblower Edward Snowden, said several nations were targets of US electronic surveillance.
The snooping included lifting data on Venezuela's oil and military deals and Mexico's drug war and energy sector as well as mapping the movements of a Marxist guerrilla group in Colombia, the newspaper said.
Mexican President Enrique Pena Nieto said on Wednesday that his government had asked for and explanation and that if the claims turn out to be true, "it would be completely unacceptable".
Pena Nieto, however, said the two allies still maintained relations of "respect and cordiality".
Globo said other countries targeted by the National Security Agency were Argentina, Ecuador, Panama, Costa Rica, Nicaragua, Honduras, Paraguay, Chile, Peru and El Salvador.
"It sends chills up my spine when we learn that they are spying on us through their intelligence services in Brazil," Argentine President Cristina Kirchner said, referring to another Globo report that the United States maintained a satellite spy base in Brasilia at least until 2002.
'Close your Facebook'
Venezuela's prisons minister on Wednesday urged citizens to shut Facebook accounts to avoid being unwitting informants for the CIA.
"Comrades: cancel your Facebook accounts, you've been working for free as CIA informants. Review the Snowden case!" wrote Iris Varela, choosing Twitter as her preferred means of communication.
The issue will be on the agenda of Friday's summit of the Mercosur trade bloc, which includes Brazil, Argentina, Uruguay and Venezuela. The leaders of Bolivia and Honduras were also invited to the talks in Montevideo.
"The Mercosur meeting is an opportunity to take a common stand. Any attack on the sovereignty of one country must be answered with great firmness, because if we lower our heads, they will walk all over us," warned Brazil's presidential chief of staff Gilberto Carvalho.
President Dilma Rousseff has ordered an investigation into the report of electronic spying on Brazilian citizens and companies.
Colombia, the top US ally in the region which has received billions of dollars in US military aid to combat drug trafficking and leftist rebels, voiced concern and said it would seek answers from the United States.
A foreign ministry statement earlier this week said that Colombia rejected "acts of espionage that violate people's right to privacy and international conventions on telecommunications".
US State Department spokeswoman, Jen Psaki, said that any answers to requests from countries such as Colombia would remain private.
The outrage comes as Snowden, who is believed to be holed up in Moscow's international airport, is considering taking asylum in Latin America after the leftist leaders of Venezuela, Bolivia and Nicaragua offered to take in the 30-year-old fugitive.