Hours after President Trump's 104% tariffs on Chinese goods went into effect, China did exactly what Trump urged it not to do: It retaliated. Beijing increased tariffs on US goods from 34% to 84%, effective Thursday. US stock index futures fell sharply with the announcement, per Reuters. Speaking before the announcement, Chinese Foreign Ministry spokesperson Lin Jian said China was firmly opposed to the "domineering and bullying behavior" by the US, per CNN. "If the US disregards the interests of both countries and the international community and insists on waging a tariff war and trade war, China will fight to the end," he said. The tit-for-tat now "threatens to bring trade between two of the world's most important economies to a standstill," per CNBC. (More tariffs stories.)