China and the United States on Tuesday resumed talks on curbing the production of ingredients to make fentanyl, as the two powers seek to rebuild frayed channels of communication on hot-button issues.

The synthetic opioid, many times more powerful than heroin, has caused an epidemic of addiction in the United States -- responsible for 100,000 overdose deaths a year, officials say.

Washington's allegations that Beijing is complicit in the trade have long been yet another source of contention between the United States and China, at loggerheads in recent years over everything from trade to human rights and the self-ruled island of Taiwan.

At a summit in November, presidents Xi Jinping and Joe Biden agreed to do more to cooperate on tackling companies that manufacture the precursor chemicals to make fentanyl and on cutting financing for the trade.

On Tuesday, a Washington delegation led by Deputy Homeland Security Advisor Jen Daskal arrived in Beijing for the inaugural meeting of a counter-narcotics cooperation working group.

She is accompanied by high-level US officials from the State Department, Treasury, Department of Homeland Security and Justice Department.

After being greeted at Beijing's Diaoyutai guesthouse by Minister for Public Security Wang Xiaohong, Daskal underscored that "synthetic drugs are killing so many thousands of people".

"I've come from Washington with a very high level delegation that represents the United States' whole-of-government approach to tackling the global challenge posed by illicit narcotics," she added.

"President Biden sent such a significant delegation to underscore the importance of this issue to the American people," she said.

Wang, in turn, said the establishing of the China-US working group represented an "important common understanding" reached by the presidents last year.

"Our cooperation once again shows that the China-US relationship gains from cooperation and loses from confrontation," he said, speaking through an interpreter.

Working-level China-US talks earlier in the day had been "in-depth" and "pragmatic", he added.

"Our two sides agreed to follow the principles of mutual respect, managing differences and mutually beneficial cooperation as we work to carry on cooperation on counternarcotics," he said.

Wang said he hoped future meetings would see two sides "accommodating each other's concerns to enhance and expand cooperation to provide more positive energy for stable, sound and sustainable China-US relations".

'Zero tolerance'

The United States says it hopes the talks will "provide a platform to facilitate ongoing coordination designed to tackle the illicit production, financing, and distribution of illicit drugs".

Xi pledged during his summit with Biden in November to clamp down on the trade.

He also said that China "deeply sympathises" with victims of fentanyl.

The US Drug Enforcement Agency in the past previously described China as "the main source for all fentanyl-related substances trafficked into the United States".

And in October, the US Justice Department slapped sanctions on more than two dozen China-based entities and individuals alleged to be the "source of supply" for many US-based narcotics traffickers, dark web vendors, virtual currency money launderers and Mexico-based criminal organisations.

Beijing has denied complicity in the deadly trade, touting its "zero tolerance" drug policies and insisting the roots of the addiction crisis lie in the United States.

Since the summit China has shut down one company, blocked some international payments and resumed sharing information on shipments and trafficking, a US official said last week.