https://www.reuters.com/article/us-usa-china-trump-telecommunications/trump-signs-order-to-safeguard-u-s-telecommunication-networks-idUSKCN1SL2QX >President Donald Trump on Wednesday signed an executive order declaring a national emergency and barring U.S. companies from using telecommunications equipment made by firms posing a national security risk, paving the way for a ban on doing business with China's Huawei Technologies Co.