China has announced a fresh round of retaliatory measures against the United States, escalating tensions between the world’s two largest economies. In response to the latest US trade sanctions, Beijing has imposed sanctions on six American companies, tightened export controls on drones and launched a series of additional trade-related actions targeting Washington. The measures were unveiled on Wednesday after the United States introduced another round of tariffs on China and more than 50 other countries as part of President Donald Trump’s broader trade strategy. The US administration has argued that the tariffs are aimed at correcting trade imbalances that it considers “unfair” to Washington.