Trump says Xi Jinping will help fight fentanyl. Will China follow through?

For years, the U.S. and China have been locked in a pattern on the deadly issue of fentanyl. The White House pressures Beijing to stop Chinese companies from exporting chemicals used to make the drug to Mexico. Beijing takes incremental steps in exchange for Washington dialing down economic pressure-only for China to drag its feet when relations deteriorate.

- Brian Spegele & Santiago Pérez

Getting China's cooperation has been a recurring challenge for U.S. presidents.

(AFP)

President Trump, after a summit on Thursday with Chinese leader Xi Jinping, said tariffs he had imposed on China over its role in the fentanyl trade would be lowered to 10% from 20% because of Beijing's "very strong action" in cracking down and Xi's commitment to do more.

It was the latest U.S. bid to win China's help to stem a scourge that has killed hundreds of thousands of Americans.

The challenge now for Trump is to make sure that China takes action—and sustains its cooperation, particularly when Beijing has consistently pushed back against U.S. tariffs.

A White House official said that the Trump administration will be setting up working groups with Chinese officials in the coming weeks to set objective measures and ensure that all sides live up to their commitments. China's Foreign Ministry also said China would work with the U.S. to implement the agreement to strengthen cooperation in the field of drug control.

China's main connection to the opioid crisis is as the source of the chemicals, known as precursors, used by Mexican cartels that produce fentanyl and smuggle the drug into the U.S. But while Trump has leaned on Mexico to mobilize law enforcement, convincing Beijing that it is in China's interests to crack down is more difficult.

China calibrates its cooperation on counternarcotics in response to the overall U.S. relationship, said Vanda Felbab-Brown, a counternarcotics expert at the Brookings Institution.