1991年6月12日,美国、加拿大、墨西哥的高级贸易官员为达成一项三国间的自由贸易协定在加拿大举行首轮正式谈判.谈判内容涉及关税、商标、劳务、投资、专利和知识产权等.谈判引起各方的关注,舆论界普遍推测,有关协定的谈判将持续1年半至3年才能最后签字. On June 12, 1991, senior trade officials from the United States, Canada, and Mexico held the first round of formal negotiations in Canada to reach a free trade agreement between the three countries. The negotiations covered tariffs, trademarks, labor, investment, patents, and intellectual property rights. The negotiations have attracted the attention of all parties. The media industry has generally speculated that negotiations on the relevant agreement will last one and a half to three years before the final signature.