美国三大股指期货大致持平，其中标普股指期货转涨，纳指期货跌0.1%。美国总统特朗普称，将在1-2周内向各国发送贸易信函。愿意延长贸易截止日期，但没必要那样做。将在两周内制定单边关税税率。

Group 1 - The U.S. stock index futures are generally flat, with S&P futures turning positive while Nasdaq futures decline by 0.1% [1] - President Trump announced plans to send trade letters to various countries within 1-2 weeks [1] - There is a willingness to extend the trade deadline, but it is deemed unnecessary [1] - A unilateral tariff rate will be established within two weeks [1]