The term "reciprocal tariffs" refers to a mechanism where a country or region imposes tariff rates on foreign products originating from other countries or regions, in response to the tariffs those counterparts levy on its own products. Based on the so-called "reciprocity" principle, this mechanism embodies the idea that "whatever tariff a country imposes on US goods, the US imposes the same rate, neither more nor less". The concept of "reciprocal tariffs"dates back to the McKinley Tariff Act of the late 19th century, which first introduced the reciprocity concept and included a "reciprocity clause". This clause empowered the president to negotiate tariffs with other countries based on the "reciprocity" principle. However, its essence was to pressure trading partners into lowering tariffs through punitive measures. At the 2018 Davos Forum, US President Trump emphasized "reciprocal tariffs," demanding absolute parity in tariff levels and trade policies between nations and their trading partners.

On February 13, 2025, US President Trump signed a memorandum, officially introducing the "reciprocal tariffs" and expanding its targets to major trading partners such as Brazil, India, and the EU. The "reciprocal tariffs" on China further escalated China-US trade friction: On February 1, citing "illegal immigration and fentanyl issues", Trump imposed an additional 10% tariff on all Chinese imports and abolish the duty-free policy for packages under US$800 (T86 customs clearance policy). On March 3, an additional 10% tariff was added due to fentanyl, raising the cumulative fentanyl levy rate on Chinese products to 20%. On April 2, the "reciprocal tariffs" was launched. A 10% benchmark tariff was set, plus a 34% additional tariff on Chinese goods, reaching a total of 54%. On April 8, the tariff increased to 84% (104% cumulatively). On April 9, it rose to 125%, with some products (e.g., syringes and lithium batteries) facing combined tax rates of up to 245%.