The top Democrat on the US Senate’s foreign policy panel urged Donald Trump on Monday not to signal any retreat from Taiwan when he hosts Chinese President Xi Jinping this week. Speaking at the Concordia Summit in New York, Senator Jeanne Shaheen said she hoped the president “will not say anything that indicates a lack of support for Taiwan” during his talks with the Chinese leader. Shaheen is the ranking member of the Senate Foreign Relations Committee, which reviews US arms sales abroad,...