Brazil’s President Dilma Rousseff has called off a state visit to the US next month in a row over allegations of American espionage.
The US National Security Agency (NSA) has been accused of intercepting emails and messages from Dilma Rousseff, her aides and state oil company, Petrobras.
The allegations were based on documents leaked by fugitive former intelligence contractor Edward Snowden.
President Barack Obama had promised to investigate the incident.
The White House said he had telephoned Dilma Rousseff on Monday to discuss the matter.
The allegations of widespread espionage against Brazilian citizens were first published in July by Rio de Janeiro-based journalist Glenn Greenwald, a reporter for the Guardian newspaper.
Glenn Greenwald alleged that the NSA accessed all internet content that Dilma Rousseff had visited online.
The documents, according to the report, were part of an NSA case study showing how data could be intelligently filtered.
Earlier this month, another report by Glenn Greenwald on Globo Television alleged that the NSA had illegally accessed data from oil company Petrobras.
The company is due next month to carry out an important auction for exploration rights of an oil field off the Rio de Janeiro state coast.
Dilma Rousseff has said that if the accusations are proven it means the NSA was involved in “industrial espionage”.
Her US state visit, starting on October 23, was to be the first by a Brazilian president since 1995.
In a statement on Tuesday, the Brazilian government said that “given the proximity of the scheduled state visit to Washington – and in the absence of a timely investigation of the incident, with corresponding explanations and the commitment to cease the interception activities” it could not go ahead as planned.
The statement said Brazil hoped the visit would take place “as soon as possible”, once the issue had been “resolved properly”.
White House spokesman Jay Carney said that the postponement had been a joint decision between Dilma Rousseff and Barack Obama, who agreed it “should not be overshadowed by any bilateral issue”.
The White House said in a statement: “The president has said that he understands and regrets the concerns [that] disclosures of alleged US intelligence activities have generated in Brazil and made clear that he is committed to working together with President Rousseff and her government in diplomatic channels to move beyond this issue as a source of tension in our bilateral relationship.”
The NSA has been accused of looking into electronic communications from what the US sees as hostile Latin American governments, such as Venezuela and Ecuador, as well as traditional allies, including Mexico.
At the G20 meeting in Russia earlier this month, Barack Obama promised to investigate the allegations of espionage against Dilma Rousseff and her Mexican counterpart, Henrique Pena Nieto.