威胁制裁，特朗普要求俄乌8月8日前达成协议，普京：如果有人对迄今俄乌和谈成果感到失望，那是因为“期望过高”

Group 1 - The core viewpoint of the articles revolves around the escalating tensions between the U.S. and Russia regarding the ongoing conflict in Ukraine, with U.S. President Trump preparing to impose new sanctions on Russia while expressing uncertainty about their effectiveness [1][4][6] - Trump's special envoy, Wittekov, is expected to visit Russia shortly before the sanctions are implemented, indicating a potential diplomatic effort to gauge Russia's stance [1][2] - The U.S. has set a deadline of August 8 for Russia and Ukraine to reach a peace agreement, with Trump emphasizing the need for negotiations to ensure peace [1][4][6] Group 2 - Reports indicate that Russia is maintaining its military advantage on the battlefield, with recent drone and missile attacks on Ukraine, which has led to increased anxiety in the U.S. [2][3] - Russian President Putin has expressed a willingness to wait for Ukraine's leadership to reconsider the timing of negotiations, suggesting that dialogue remains essential for peace [3][4][6] - The Russian military claims to have gained control over strategic areas in eastern Ukraine, which could represent a significant military victory for Russia [3][4]