America's National Security Agency has used secret technology to spy on computers that were not even connected to the internet, a US media report says.
The New York Times said 100,000 machines were fitted with small devices that emitted radio waves to transmit data without the need for the machine to be connected to a wider network.
Citing documents from whistleblower Edward Snowden the paper said targets included the Chinese and Russian military as well as drug cartels.
The newspaper also said the same software could also be used to create a digital highway for launching cyber attacks.
In a statement made to newspaper, an NSA spokeswoman said none of the targets were in the United States.
On Friday, US President Barack Obama is expected to address concerns over NSA activity and restrictions on the scope of collecting bulk telephone data will feature, the paper said.
Tighter controls on foreign surveillance would be implemented - an attempt, the paper suggests, to dampen the political fall-out from revelations the US had obtained data from the communication tools of world leaders without their knowledge.