Washington: US authorities announced a ban Friday on the import or sale of communications equipment deemed “an unacceptable risk to national security” — including gear from Chinese giants Huawei Technologies and ZTE. Both firms have been on a roster of companies listed as a threat by the Federal Communications Commission (FCC), and the new rules bar future authorizations of their equipment. The move is the latest in a series of actions to limit the access of Chinese telecoms firms in United States networks, and comes amid a long-running standoff between the world’s two biggest economies. US officials have shown growing…