Trump cited the fentanyl issue as the reason for imposing a 10% tariff on all Chinese imports in early February, on top of any existing duties. He doubled that to 20% earlier this month. He also has cited fentanyl, along with other reasons, for imposing tariffs on Canada and Mexico.

China said on Wednesday that the U.S. has undermined bilateral counter-narcotics cooperation by imposing tariffs on Chinese goods over fentanyl, calling on Washington to stop using the issue as a bargaining chip to "blackmail" the country.

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.