Brasilia, Sep 4 (IANS/EFE): Brazil President Dilma Rousseff's scheduled state visit to the US may be in jeopardy after revelations that Washington spied on her, according to an official source.

"The next steps will decide" whether Rousseff travels to Washington next month as planned, the source said Tuesday.

The Brazilian government will make a decision based on the content of the written explanation it has demanded from the US, he said.

Rousseff and US President Barack Obama will both be in St. Petersburg, Russia, this week for the G20 economic summit, but there are no plans for a bilateral meeting, according to the source.

The US National Security Agency intercepted telephone calls and e-mails of Rousseff and Mexican leader Enrique Peña Nieto, Brazil's Globo television said this week, citing documents from whistleblower Edward Snowden.

Globo's flagship news magazine, 'Fantastico', referred to a June 2012 "top secret" slide presentation touting NSA's ability to access the content of the voice and e-mail communications of both Rousseff and Peña Nieto.

The slides were among the documentation Snowden, a former US intelligence contractor, provided to Brazil-based US journalist Glenn Greenwald.

Brazilian Foreign Minister Luiz Alberto Figueiredo summoned US Ambassador Thomas Shannon Monday to discuss the Globo report.

"I made it clear that the violation of the president's communications is inadmissible, unacceptable, and constitutes a violation of Brazilian sovereignty," the minister said.

Figueiredo also told Shannon that Brazil wants a written explanation of the spying.