Huawei's chip-making subsidiary Hisilicon said that the supply of most of its products will not be affected by the U.S. ban, thanks to its years-long efforts to develop backup products for U.S. supplies. 

In a letter issued to its employees made public on Friday morning, Hisilicon's President He Tingbo, wrote that the company had long ago set up a survival plan for the scenario that one day chips and technology from the U.S. could be unattainable. 

On Wednesday, Huawei and its 70 affiliates were added by the U.S. to its so-called "Entity List," a move that bans the company from buying parts and components from American firms without U.S. government approval. Another Chinese telecom giant ZTE was crippled when it was included in the list in March 2016.

He said that the company had started to develop its own substitutes many years ago in spite of mounting difficulties and challenges, and is now more than ready to fill the shortfall in parts supply, which is expected to result from the U.S. ban.

He also said that Huawei would further strengthen innovation and technological independence.  

Huawei's rotating chairman Hu Houkun on Wednesday said in an internal mail that the block is the latest step by the U.S. government to continue crackdown on Huawei, for political purpose.  

However, "the company's operation will not be greatly affected," said Hu facing the potential concerns over Huawei, as it has invested heavily in research and development as well as business continuity, and made sufficient preparations for extreme cases.

China urges the U.S. to stop the mistake of carrying out the executive order, which is "an abuse of national security and unilateral trade sanctions," said Chinese Ministry of Commerce spokesperson Gao Feng in a media conference.

The restrictions "will only force the U.S. to use inferior and expensive alternative equipment and ultimately hurt the interests of U.S. consumers," Huawei said in a statement.