There is no illegal trade in fentanyl between China and Mexico.China’s foreign ministry said on Thursday in response to a letter from the Mexican president asking Beijing to help curb illegal flows of the deadly drug.

China was not notified by Mexico about no seizures of fentanyl from Chinasaid ministry spokesman Mao Ning at a regular briefing.

“America must solve its own problems and take more significant steps to tighten regulation within their borders and reduce demand,” Mao said, calling drug use “a problem that has arisen in the United States.”

The President of Mexico said last Tuesday that he Letter to Chinese President Xi Jinping urging help control the supply of fentanyl, defending himself against criticism in the United States that Mexico is not doing enough to stop the trafficking of synthetic opioids.

Fentanyl, used in hospitals for anesthesia and pain relief, has become one of the main black market drugs in the US. Mexican drug cartels participated more and more in their illegal trade.

Overdoses of this opioid more than 100,000 people died in US fiscal year 2022, according to the US Centers for Disease Control and Prevention.

President Andrés Manuel López Obrador, in a March 22 letter, defended efforts to curb the supply of the drug while lashing out at United States critics, some of whom want Washington’s military intervention in Mexico’s affairs.

letter and China’s response made no mention of the supply of chemicals used to make a powerful sedative.