US

China disputes US claim it's top source of synthetic drugs

  • FILE - In this Oct. 26, 2016, file photo, a man drinks tea near a computer screen displaying websites of companies selling carfentanil online on a train leaving Beijing. U.S. assertions that China is the top source of the synthetic opioids that have killed thousands of drug users in the U.S. and Canada are unsubstantiated, Chinese officials told the Associated Press. (AP Photo/Ng Han Guan, File)

    FILE - In this Oct. 26, 2016, file photo, a man drinks tea near a computer screen displaying websites of companies selling carfentanil online on a train leaving Beijing. U.S. assertions that China is the top source of the synthetic opioids that have killed thousands of drug users in the U.S. and Canada are unsubstantiated, Chinese officials told the Associated Press. (AP Photo/Ng Han Guan, File)  (The Associated Press)

  • FILE - In this Wednesday, Sept. 21, 2016 file photo, Xu Liqun, center, president of Hangzhou Reward Technology, speaks at the company's booth during the China International Chemical Industry Fair in Shanghai, China. U.S. assertions that China is the top source of the synthetic opioids that have killed thousands of drug users in the U.S. and Canada are unsubstantiated, Chinese officials told the Associated Press. (AP Photo/Andy Wong, File)

    FILE - In this Wednesday, Sept. 21, 2016 file photo, Xu Liqun, center, president of Hangzhou Reward Technology, speaks at the company's booth during the China International Chemical Industry Fair in Shanghai, China. U.S. assertions that China is the top source of the synthetic opioids that have killed thousands of drug users in the U.S. and Canada are unsubstantiated, Chinese officials told the Associated Press. (AP Photo/Andy Wong, File)  (The Associated Press)

  • FILE - In this June 27, 2016 file photo provided by the Royal Canadian Mounted Police, members of the RCMP go through a decontamination procedure in Vancouver after intercepting a package containing approximately 1 kilogram (2.2 pounds) of the powerful opioid carfentanil imported from China. U.S. assertions that China is the top source of the synthetic opioids that have killed thousands of drug users in the U.S. and Canada are unsubstantiated, Chinese officials told the Associated Press. (Royal Canadian Mounted Police via AP, File)

    FILE - In this June 27, 2016 file photo provided by the Royal Canadian Mounted Police, members of the RCMP go through a decontamination procedure in Vancouver after intercepting a package containing approximately 1 kilogram (2.2 pounds) of the powerful opioid carfentanil imported from China. U.S. assertions that China is the top source of the synthetic opioids that have killed thousands of drug users in the U.S. and Canada are unsubstantiated, Chinese officials told the Associated Press. (Royal Canadian Mounted Police via AP, File)  (The Associated Press)

Chinese officials tell the Associated Press that U.S. assertions China is America's biggest source of deadly synthetic opioids are unsubstantiated.

Federal officials point to China as the main source of fentanyl, fentanyl analogs and fentanyl precursors that end up in North America. Such synthetic opioids have killed thousands of drug users in the U.S. and Canada.

China's National Narcotics Control Commission told the U.S. Drug Enforcement Administration in a fax dated Friday that such statements "lack the support of sufficient numbers of actual, confirmed cases." The letter, which the commission also sent to the AP, urged the U.S. to provide more evidence.

DEA officials said their casework and investigations consistently lead back to China. DEA data also shows that when China regulates synthetic drugs, U.S. seizures plunge.