On November 30, 2018, Canada, Mexico, and the United States signed an agreement renegotiating the North American Free Trade Agreement (NAFTA). By the spring of 2020, all three countries had approved this agreement—known in the United States as the United States-Mexico-Canada Agreement (USMCA)—through their respective domestic ratification processes. The USMCA entered into force on July 1, 2020, amid extended U.S.-Mexico and U.S.-Canada border restrictions due to the COVID-19 pandemic. On August 6, 2020, President Trump imposed tariffs on Canadian aluminum—tariffs that his administration had previously put in place in 2018 but had removed in 2019 in order to smooth the USMCA's path to ratification.

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美国-墨西哥-加拿大协定生效

2018 年 11 月 30 日，加拿大、墨西哥和美国签署了重新谈判北美自由贸易协定 (NAFTA) 的协议。到 2020 年春天，这三个国家都通过各自的国内批准程序批准了该协议——在美国被称为美国-墨西哥-加拿大协议 (USMCA)。由于 COVID-19 大流行，美国-墨西哥和美国-加拿大边境限制延长，USMCA 于 2020 年 7 月 1 日生效。2020 年 8 月 6 日，特朗普总统对加拿大铝征收关税——他的政府此前已于 2018 年实施但于 2019 年取消关税，以便为 USMCA 的批准铺平道路。