Brazil will set up a certification center to strengthen data security and prevent surveillance in online communications, the army's Science and Technology Department announced on Monday.

Brazil's certification center will be operational by next year to certify security equipment that can protect information from espionage, head of the department Sinclair Mayer told a Congress hearing over the case of recently-disclosed US intelligence agencies' espionage in Brazil.

The move is aimed at preventing unsafe equipment from being used in the country, Mayer added.

The US intelligence agencies had been spying on Brazilian companies and citizens via online monitoring, according to information leaked by former US National Security Agency contractor Edward Snowden.

US Secretary of State John Kerry, who visited Brazil on Tuesday, argued that the surveillance was set up after 9/11 terror attack to prevent terrorist attacks, and will continue.