WASHINGTON (Reuters) - The Democratic National Committee warned party candidates running in November elections not to use devices made by Chinese telecommunications companies ZTE Corp and Huawei Technologies because they pose a security risk, a Democratic source said on Friday. U.S. lawmakers and the Trump administration have pressured U.S. companies to not sell Huawei or ZTE (000063.SZ) products, saying they potentially could be used to spy on Americans. Earlier this year they pushed AT&T (T.N) to drop a deal with Huawei to sell its smartphones in the United States.