A day after President Xi Jinping and Vice President Joe Biden agreed that Beijing would stem the export of items used to make the opioid fentanyl, the government warned Chinese chemical companies that if they manufacture or sell precursor chemicals for illicit drugs, they could face criminal charges. In a circular issued on Thursday, the office of the China National Narcotics Control Commission warned any person or company, including postal and logistics firms, that is aware of the sale, transportation,
