UPS and FedEx cargo aircraft.
President Donald Trump urged major US package dealers to "search for and deny" packages from China containing the drug fentanyl.
In a series of tweets asking Friday for US companies to look for "an alternative to China," Trump specifically pointed out FedEx, UPS, Amazon and the United States Postal Service. China is the largest source of fentanyl for the United States, according to a 201
"I order all carriers, including Fed Ex, Amazon, UPS and Post Office, to search for and reject …. all deliveries of Fentanyl from China (or anywhere else!)," Trump said.
It is unclear whether Trump's statements will be followed by official guidelines from federal agencies.
UPS told CNBC in a statement that it "complies with all applicable laws and administrative orders of the authorities of the countries in which we do business. We work closely with regulatory authorities to monitor for banned substances."
FedEx said in a statement that it "already has comprehensive security measures in place to prevent the use of our networks for illegal purposes. We follow laws and regulations wherever we conduct business and have a long history of close cooperation with the government."
"FedEx supported the implementation of STOP law and encourages faster implementation and enforcement of regulations to protect the health and safety of the American people, "the company continued, referring to legislation signed by Trump in October last year.
Amazon and the Postal Service were not immediately available for comment.
Fentanyl is a synthetic opioid that can be 100 times more potent than morphine. The Department of Homeland Security considered labeling fentanyl as weapons of mass destruction earlier this year. Only $ 5,000 can buy enough fentanyl on the Chinese market to provide lethal doses to half a million people. The Centers for Disease Control and Prevention estimated that there were around 48,000 overdose deaths in 2017 involving all opioids.
Shares of FedEx and UPS fell by about 3% after tweets and Amazon's shares fell by about 2% on the news. The broader market also fell, with the Dow Jones Industrial Average emitting close to 500 points or 1.8%.
This is not the first time carriers are caught in the middle of a trade dispute. FedEx is facing investigation by the Chinese government for malpractice packages containing products made by Huawei, a Chinese technology company that Trump has called a "national security threat." FedEx said the shipping problems were malfunctions.
FedEx also sued the Department of Commerce in June over the Ministry's regulations on exports, saying they created an "impossible burden" for the company.
The Trump administration has prioritized cutting down on Chinese exports of fentanyl and its precursor chemicals. Last year, Trump asked China to seek the death penalty for fentanyl distributors, saying he had reached an agreement with President Xi Jinping to take action against the drug was "very exciting." Earlier this year, China had announced that it would expand its control of fentanyl-related drugs by adding it to the supplementary list of controlled drugs.
In Trump's series of tweets, he also said that he ordered US companies to find alternatives to their business in China immediately and begin producing products in the United States