China curbs drug precursor exports before Xi-Trump visit

China announced immediate export restrictions on Tuesday for two types of precursor chemicals that can be used to make drugs, days before President Xi Jinping is expected to meet US President Donald Trump in Washington.

China's commerce ministry said the substances will require applications before they can be exported to the United States, Mexico or Canada.

China is described as the primary origin of precursor chemicals used to make fentanyl, a potent opioid at the centre of a drug epidemic in the United States. Shipments of the substances from China have repeatedly complicated relations between Washington and Beijing, while China says it cracks down heavily on the drug trade.

Xi's expected Washington visit is set to include talks with Trump on issues including trade, artificial intelligence and the US war with Iran.

In May, China imposed export controls on another set of drug precursor chemicals shortly after a Trump visit to Beijing that included talks with Xi. Trump also imposed additional tariffs on Chinese goods last year in retaliation for China's role in the fentanyl epidemic, but the US Supreme Court struck down the levies in February.