(CNN) The nation's top drug officer is visiting China for the first time in more than a decade to discuss banning more of the synthetic drugs being manufactured by chemists there and illegally sold in the United States.

Acting Drug Enforcement Administration Administrator Chuck Rosenberg will visit Hong Kong, Guangzhou and Beijing over three days starting Monday.

Rosenberg was invited by the Chinese Ministry of Public Security and its Narcotics Control Bureau after a Chinese delegation visited Washington in September.

He will meet with his Chinese counterparts in narcotics, customs and border patrol, and the justice department.

The visit comes after a productive 18 months for Chinese-American relations on the subject of combating synthetic drug sales. After China's 2015 ban on 116 synthetic drugs -- including flakka -- the US saw a significant drop

"The change was just immediate in what we saw in America," DEA spokeswoman Barbara Carreno said. "The stuff just disappeared, and we're hoping to see some more of that."

Carreno said the purpose of the visit is to push for more substances to be banned, especially synthetic fentanyl, an incredibly deadly drug that can poison and kill in very small doses. It can be 50 times more potent than heroin.

Fentanyl death rates have become alarming in the United States. US officials say Chinese manufacturers are selling synthetic fentanyl to Mexican cartels. Many times, other drugs are cut with synthetic fentanyl, and users are sometimes unaware they are taking a deadly dose.

"We're encouraging them to control more substances that are illegal here even if they're not illegal there," Carreno said.

The meetings will also include discussions on new psychoactive substances and money-laundering activities.

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In addition to an office in Beijing, the DEA is opening a second China office within the consulate in Guangzhou.

After three days in China, Rosenberg will stop in Bangkok to meet DEA officials there and with representatives of the Royal Thai Police and its Narcotics Suppression Bureau. The DEA has a bureau in Bangkok and a longstanding working relationship with Thai officials dealing with the trafficking of opium through the Golden Triangle.