He said he had “many discussions” with Americans on the opioid problem and made “personal efforts” to facilitate dialogue between the US Congress and China’s National Narcotics Control Commission.

“The fentanyl crisis in the United States was not created by China,” he said, adding that his country had done all it could to help “out of goodwill”.

“So just think how shocking it was for China, for all these efforts, to be sanctioned by the United States in May 2020, with its essential institutions on fentanyl profiling and control, such as the Institute of Forensic Science of China’s Ministry of Public Security and the National Narcotics Laboratory, added to America’s ‘entity list’, only to curb China’s capability to fight narcotics,” the ambassador said.

China turns fentanyl overdose problem back on US

The two institutions along with seven other Chinese companies and entities were targeted by the US Commerce Department over their links to alleged human rights abuses in Xinjiang.

Qin also said “some Americans” and the US media had made “false and misleading claims” that “China is the primary source of fentanyl in the US” or that it was shipping drugs as a “payback for the opium wars”.

“We hope that the United States will act to stabilise and improve its relations with China and lift the sanctions on Chinese institutions to remove obstacles for such cooperation to proceed,” he said.

Rahul Gupta, director of the White House Office of National Drug Control Policy, said on Wednesday that Beijing’s decision to stop working with the US after Pelosi’s visit, was “a pretext to step back from the cooperation”.

He added: “We are working hard to … be able to have those conversations.”

03:56

Addicted to fentanyl: how a drug from China is fuelling America’s opioid crisis

Addicted to fentanyl: how a drug from China is fuelling America’s opioid crisis

In 2021, nearly 108,000 people in the US died of drug overdoses, about two-thirds of which involved fentanyl or other ­synthetic opioids, according to the US Centres for Disease Control and Prevention.

Cooperation on anti-narcotics measures, especially fentanyl, used to be a rare bright spot in the troubled US-China relationship.

In 2019 Beijing also placed fentanyl on a list of controlled substances and according to Gupta, the Chinese supply of fentanyl to the US had dropped to nearly zero by the end of that year.

The US-China Economic and Security Review Commission said in a report last year that China remained “the primary country of origin” for fentanyl trafficking in the US, and that Mexican drug cartels were getting precursor chemicals from China.

But Qin told Newsweek: “The fact is, however, that China has never received any report or data from Mexico on the use of Chinese precursor chemicals for drug production there, nor has the US provided any evidence about the flow of Chinese chemicals into Mexico for fentanyl production.”

He also dismissed US requests that China should take stronger measures as unreasonable.

The Chinese suppliers fuelling America’s fentanyl epidemic

“According to international practices, it is up to the importer and importing country to ensure that imported goods are not used for illegal purposes, not the exporter. Taking one step back, given the flow of international trade, it is simply impossible for the exporter to thoroughly verify its client located in a different territory. Mexico is a sovereign country; China has no right or capability to fulfil the responsibility on its behalf,” Qin said.

He did not directly address China’s decision to suspend cooperation on fighting the illicit drugs trade.

In August foreign ministry spokesman Wang Wenbin said “the responsibility for undermining China-US counternarcotics cooperation is entirely on the US”, also citing US sanctions.