Brazil's President Dilma Rousseff has accused the United States of spying on oil giant Petrobras for its own "economic and strategic" reasons - and not for national security purposes.
The latest allegations of online snooping by the National Security Agency emerged on Sunday night when TV Globo reported Brazilian oil giant Petrobras - world leader in deep-water oil exploration - was among those targeted, along with Google and the French foreign ministry.
Rousseff said in a statement on Monday that "if the facts are confirmed, it would be clear the espionage was not for security or the 'fight against terrorism', but to respond to economic and strategic interests".
"Without doubt, Petrobras is not a threat to the security of any country," the president said.
These attempts to steal "data and information are incompatible with democratic co-existence between friends", she added, and said Brazil would "take all measures to protect the country, the government and its companies".
Petrobras said in a statement that it has highly qualified and constantly updated systems to protect its internal communications network.
Brazil's foreign minister headed to the United States on Monday to meet this week with National Security adviser Susan Rice over the spying row.
The meeting between Luiz Alberto Figueiredo and Rice is planned for today or tomorrow in Washington, though the date has not been confirmed, a spokesman for the Brazilian foreign ministry said.
TV Globo said it obtained the information for its story from Glenn Greenwald, a blogger and columnist for The Guardian newspaper, who got secret files from former US intelligence contractor Edward Snowden.