China is demanding an explanation from Washington over media reports that the US National Security Agency hacked into the e-mail servers of Chinese tech giant Huawei and targeted top Chinese officials and government institutions.

Foreign Ministry spokesman Hong Lei said Beijing is deeply concerned about the charges and demands that any such spying be stopped.

"Recently, the international media has put out a lot of reports about the eavesdropping, surveillance and stealing of secrets by the United States of other countries, including China," he told a regular briefing.

"China has already lodged many complaints with the United States about this. We demand that the United States make a clear explanation and stop such acts."