"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. Brazil will redouble its efforts to adopt legislation, technologies and mechanisms to protect us from the illegal interception of communications and data.
My Government will do everything within its reach to defend the human rights of all Brazilians and to protect the fruits borne from the ingenuity of our workers and our companies."
She called on the United Nations to take action to regulate the conduct of states with interception technology and said Brazil would put up a proposal for a multilateral framework to govern Internet use and ensure data was protected.
Mr Key said he had not had time to analyse Rousseff's comments but her objections to the US spy agency's actions were not new - she had cancelled a proposed trip to the US in protest.
"Obviously she's taken a pretty strong view on the fact that its possible the United States had undertaken some activity looking at Brazil."
Mr Key has repeatedly refused to say what information New Zealand shared with its Five Eyes partners, but has said that the new GCSB Act will not allow mass surveillance of New Zealanders, including metadata, without a warrant.