WASHINGTON (Reuters) -The United States on Wednesday added more than a dozen Chinese companies to a list created by the Defense Department to highlight firms it says are allegedly working with Beijing's military, as part of a broader effort to keep American technology from aiding China. New additions to the list, first reported by Reuters, were posted on the Department of Defense website and include memory chip maker YMTC, artificial intelligence company Megvii, lidar maker Hesai Technology and tech company NetPosa. Amid strained ties between the world's two biggest economies, the updated list is one of numerous actions Washington has taken in recent years to highlight and restrict Chinese companies that is says may strengthen Beijing's military.