China’s foreign minister Wang Yi warned the US to approach Taiwan affairs with “utmost caution” in a call with Secretary of State Marco Rubio, calling for Washington to expand cooperation and manage risks with Beijing.According to Chinese state news agency Xinhua, the two top diplomats held a “positive and constructive” phone call on Tuesday. It is the first reported cabinet-level communication since US President Donald Trump’s landmark visit to China in mid-May.During that visit, the two...