"People around the globe deserve to know that their information is secure and Facebook will keep urging the US government to be more transparent about its practices and more protective of civil liberties," the statement continued.

NSA targeted Chinese tech giant Huawei

Huawei's operating profit jumps in 2013

Huawei has long been a bogeyman for the US government and lawmakers in their attempt to vilify China as a source of cyber espionage.

In October 2012, a US House Intelligence Committee report advised US companies to avoid doing business with Huawei and ZTE Corp, another Chinese telecom giant, because of possible national security threats, an allegation unsubstantiated by evidence.

Huawei has dismissed the allegation as groundless. However, its business has been negatively affected over the years because of the concerns in the US.

Zhu Zhiqun, a professor of political science at Bucknell University, in Lewisburg, Pennsylvania, said the US government likes to paint itself as the victim in cyber spying, especially between the US and China.

"But few people with common sense would doubt that the US intelligence has one of the most sophisticated and aggressive espionage networks around the world," he said.

"Earlier it was revealed the NSA spied on US allies such as Germany and its leaders. So the latest revelation that NSA spied on Huawei and Chinese leaders should not come as a surprise at all."

Zhu said the revelation is an embarrassment to those who singled out Huawei as the culprit. "It will be interesting to see how US officials, members of Congress and security experts defend the extensive US espionage in China and elsewhere," he said.

Groundless report threatens US jobs: Huawei	Huawei set to become No 2 smartphone vendor