Rousseff remained firm as she spoke to reporters at the end of the G-20 summit.
"I think is very serious to spy on a democratic country, very serious. I don't see how someone can defend spying on a democratic country, or spying on the privacy of people," she said.
"I made him (Obama) see that the relationship that we had, based on the fact that we are big democracies in this part of the world, is incompatible with the act of spying."
"President Obama told me and repeated that he wants to create political conditions for my trip to the United States," she said. "I want to know everything that they have. Everything."
Brazil's minister for external relations, Luiz Alberto Figueiredo, is expected to meet with the U.S. National Security Adviser Susan Rice on Sept. 11 to discuss the matter.