The US National Security Agency wiretapped several key Brazilian government officials including President Dilma Rousseff, her secretary and her chief of staff, according to WikiLeaks documents disclosed Saturday.

The group says the NSA eavesdropped on 29 key Brazilian government phone numbers, listening in on conversations taking place on Rousseff's palace office line and her presidential jet phone as well as on phones of Brazil's foreign minister, ambassadors and military chiefs, US Today newspaper reported Sunday.

The United States also waged an "economic espionage campaign" against Brazil by spying on those responsible for managing Brazil's economy, including the head of its Central Bank, WikiLeaks says.

"Our publication today shows the US has a long way to go to prove its dragnet surveillance on 'friendly' governments is over," WikiLeaks founder Julian Assange said in a statement.

"The US has not just (been) targeting President Rousseff but the key figures she talks to every day."

He added that any US assurances of ceasing its targeting of Rousseff cannot be trusted, and Rousseff herself must guarantee that the spying has stopped on her and on all Brazilian issues.

WikiLeaks further detailed the NSA's "intensive interception" of Brazilian phones, saying the agency targeted Brazil's diplomacy by spying on the country's ambassadors to the United States, Germany, France, the European Union and Geneva.