China has reacted negatively to such a decision by US officials. Most recently held historical a meeting between the authorities of China and Taiwan, which gave rise to talk about the possibility of establishing full-fledged diplomatic relations between Beijing and Taipei. After the decision of the American authorities to implement weapons for the Taiwanese army in Beijing, they believe that this is throwing relations to the previous level. Recall that official Beijing does not recognize Taiwan as an independent state.
At the same time, in Washington itself, they have already managed to declare that the sale of arms to Taiwan "should in no way affect relations with China." At the US State Department, they say that this step is in no way aimed at somehow ignoring the territorial integrity of China. It should be noted that the USA Taiwan is an independent state that recognizes and maintains relations at the interstate level.
China has said that US actions may affect Sino-US relations.