Chinese telecom giants Huawei and ZTE pose a security threat to the United States and should be barred from US contracts and acquisitions, a yearlong congressional investigation has concluded. A draft of a report by the House Intelligence Committee, obtained Sunday by AFP, said the two firms "cannot be trusted" to be free of influence from Beijing and could be used to undermine US security. "Based on available classified and unclassified information, Huawei and ZTE cannot be trusted to be free of foreign state influence and thus pose a security threat to the United States and to our systems," the draft document said. The congressional panel launched its probe over concerns that Beijing could use the fast-growing firms for economic or military espionage, or cyber attacks. Both Huawei and ZTE have denied any ties with the Chinese government. Top executives of the firms appeared at a hearing held by the panel last month, stressing that they were focused on business, not politics. Huawei reiterated that position in response to queries. "The integrity and independence of Huawei's organization and business practices are trusted and respected across almost 150 markets," Huawei vice president William Plummer said in an emailed statement. "Purporting that Huawei is somehow uniquely vulnerable to cyber mischief ignores technical and commercial realities, recklessly threatens American jobs and innovation, does nothing to protect national security, and should be exposed as dangerous political distractions." ZTE did not immediately respond to a request for comment.