The Trump administration on Tuesday announced a ban on the import of new foreign-made humanoid robots into the United States, saying the devices pose “unacceptable risks” to the country’s national security. The ban covers advanced robots, including humanoid and four-legged machines, many of which are manufactured in China. China is one of the United States’ main competitors in the development of robotics and artificial intelligence. Chinese exports have come under increasing scrutiny as the Trump administration continues its efforts to address trade imbalances with China, the world’s second-largest economy. Chinese technology companies have made rapid progress in developing humanoid robots for use in factories, homes and other settings.