美国总统特朗普在信中表示，如果墨西哥在打击贩毒集团、阻止芬太尼流入方面取得实质性成效，或欧盟愿意向美国开放贸易市场、取消关税、非关税政策及其他贸易壁垒，美国或将考虑对关税政策作出相应调整。

Core Viewpoint - The U.S. may consider adjusting its tariff policies based on Mexico's effectiveness in combating drug cartels and preventing fentanyl influx, or if the EU is willing to open its trade market to the U.S. by removing tariffs and other trade barriers [1] Group 1 - President Trump indicated that substantial progress by Mexico in fighting drug trafficking could influence U.S. tariff policies [1] - The potential for tariff adjustments is also linked to the EU's willingness to eliminate trade barriers with the U.S. [1]