China has reiterated it could take “necessary countermeasures" after U.S. President Donald Trump decided to impose a 10% tariff on China for allegedly doing too little to stem the production of precursor chemicals for the drug fentanyl.

As the leaders of Canada and Mexico rushed to respond after Donald Trump started a new trade war, Chinese President Xi Jinping took a breath before his nation announced any concrete retaliation.

China chose swift retaliation for trade measures in the first Trump administration, but that led to an upward spiral of trade measures and much broader tariffs.