The U.S., where fentanyl abuse has been a major cause of death, has pushed China for deeper law enforcement cooperation, including tackling illicit finance, arrests of rogue chemists and raids of labs involved in the production of precursors.

China will take all necessary measures to safeguard its rights and interests, the Chinese foreign ministry said on Wednesday, after U.S. President Donald Trump increased tariffs on all U.S. steel and aluminium imports.

Fresh tariffs on Chinese imports put U.S. retailers in a tough spot. Raising prices risks the ire of President Trump and American consumers, but getting suppliers to bear the burden isn’t simple either—and in Walmart's case,