Brazilian President Dilma Rousseff has said her U.S. countepart Barack Obama has promised to take direct and personal responsibility for investigating the revelations that her personal phone, e-mails and text messages were targeted by the National Security Agency (NSA).

In an unscheduled meeting on the sidelines of G-20 Summit at St. Petersburg on Friday, Mr. Obama tried to placate the Brazilian leader. “President Obama said to me that he would assume direct and personal responsibility for full clarification of the facts and take steps to remedy the problem”, she said.

She also said Mr. Obama had promised to give an answer by Wednesday. “I will wait for his answer before making a decision on my travel to U.S. I haven’t made the final decision yet,” she said, when asked if she would go ahead with her Washington trip.

She said it depended on “political conditions” that need to be restored by Washington. She said the U.S. had no justification for spying on Brazil for alleged national security issues since the country “does not harbour terrorist groups” and it prohibits nuclear weapons in the Constitution.

This leads to the conclusion, she added, that the spying activities were linked to “geopolitical factors, strategic factors or economic and commercial factors”.

The tense relations, sparked by NSA disclosures since July, became worse last Sunday when it was revealed by Globo TV that the NSA had spied on e-mails, phone calls and text messages of Ms. Rousseff.

The imbroglio has some in Brasilia toying with the idea of sending a strong message to the U.S. A government source close to the Brazilian President had told a news agency on Wednesday that she feels “patronised” by Washington.