The US has made it clear to China that failing to coordinate on the fentanyl issue comes at a cost, according to Nicholas Burns, American’s former ambassador to Beijing.

The U.S. is "smearing and shifting blame onto China" over the fentanyl issue, a spokesman for the Chinese foreign ministry said, after the Trump Administration had hailed the progress made with Beijing on the crisis at trade talks in Geneva.

The responsibility of tackling the fentanyl issue in the United States lies within the U.S. itself, China's foreign ministry said on Tuesday, rejecting the punitive tariffs Washington imposed on Beijing for not stemming the inflow.