In the United States, while the Constitution grants Congress the power to regulate foreign commerce and set tariffs, it has delegated significant authority to the President to adjust tariff rates, particularly for trade negotiations, national security (Section 232), and unfair trade practices (Sections 301, 201). The President works with agencies like the U.S. Trade Representative (USTR) and the International Trade Commission (USITC)
如果说需要考虑什么，是其他国家会考虑增加出口量。
关税问题影响的是美国进口商，这对其他国家有什么关系？
因为美国海关不得不降低进口税。