Brazil's president has delivered a stinging rebuke to the United States over its surveillance programme that has swept up data from billions of telephone calls and emails that have passed through Brazil, including her own.
Addressing the UN General Assembly on Tuesday, Dilma Rousseff also called on the global body to create a framework of Internet regulation to halt the US and other nations from using it as the "new battlefield" of espionage.
The Brazilian president accused the US of violating Brazil's sovereignty with what she called a "grave violation of human rights and of civil liberties".
"In the absence of the respect for sovereignty, there is no basis for the relationship among nations," Rousseff said.
"Friendly governments and societies that seek to build a true strategic partnership, as in our case, cannot allow recurring illegal actions to take place as if they were normal. They are unacceptable."
Last week, she shelved an upcoming state trip to the US in a show of anger over the National Security Agency programme.
Brazil is an important hub for trans-Atlantic fiber optic cables. The NSA, tasked with intercepting potential terror communications, also reportedly hacked into the computer network of state-run oil company Petrobras.
Rousseff said the NSA also collected economic and strategic corporate data, as well as messages by Brazilian diplomats, including to the United Nations, and from her own office.
She said Brazilian citizens' personal data "was intercepted indiscriminately".
"The arguments that the illegal interception of information and data aims at protecting nations against terrorism cannot be sustained," Rousseff said. Brazil "knows how to protect itself. We reject, fight and do not harbor terrorist groups," she added.
Rousseff said she has demanded an apology from the US and assurances that the electronic snooping will stop.
The Obama administration has said its surveillance programme does not examine the context of the intercepted messages without evidence they are suspicious, though reports in Brazilian media outlets based on leaked NSA documents indicated that Rousseff's own emails were read.