Chinese public health officials announced a blanket ban on all kinds of the powerful opioid fentanyl Monday, fulfilling a promise President Xi Jinping made to President Trump in December.

China already treats many types of fentanyl as controlled substances but only bans them one-by-one after time-consuming reviews. New variants are made before the old ones can be controlled. The regulation, which goes into effect May 1, will close loopholes that manufacturers in China have used before, including changing the fentanyl product just enough so it is no longer illegal.

Sen. Rob Portman, R-Ohio, applauded China’s announcement, calling it “a powerful first step” to curbing fentanyl-related deaths.

Ohio is among the top five states with the highest rates of opioid-related deaths, and Ohio has seen a recent uptick in fentanyl-laced cocaine.

Lawmakers have recently tried to crack down on security through the postal service. The Department of Homeland Security has said many times that most fentanyl is produced in China and shipped to Mexico or Canada to then be smuggled into the United States.

Liu Yuejin, a deputy commissioner at the China National Narcotics Control Commission, repeated the Chinese position that overprescription and an American culture of addiction were to blame for the opioid epidemic, not Chinese chemists shipping fentanyl to the U.S.

Liu said trafficking to the U.S. through the mail was "extremely limited."

“If the United States truly wants to resolve its fentanyl abuse problem, it needs to strengthen its domestic work,” he said.

This most recent promise from China, though, sounds familiar to the one made to former President Barack Obama in 2016. The Chinese government never made a plan to curb opioid exportation to the U.S. or followed up with the president. China's pledge Monday was to target all shipments of types of fentanyl bound for the U.S. and to communicate with U.S. law enforcement about seizures.

Fentanyl, a synthetic opioid, is about 100 times stronger than morphine and is commonly added to heroin. Because fentanyl is often laced with heroin or cocaine, some take it unknowingly. Over 19,000 people in 2016 died due to synthetic opioid overdose.