Senior US and Chinese officials have agreed their countries will continue dialogue and cooperation on drug-related issues, such as the handling of fentanyl.

China's state-run Xinhua news agency reported that the country's Minister of Public Security Wang Xiaohong and US Homeland Security Secretary Alejandro Mayorkas held talks in Vienna, Austria, on Sunday.

Fentanyl is used as a painkiller in medical treatment. But excessive consumption has been a problem in the United States.

Xinhua reported that Wang raised other concerns during the talks, urging the US to stop harassing and interrogating Chinese students for no reason, and to lift visa restrictions imposed on Chinese institutions and personnel.

Observers say China aims to secure certain concessions from the US by demonstrating its proactive approach to drug control.

There have been a number of cases in which fentanyl, produced using materials made in China, was smuggled into the US.

The two countries agreed to set up a working group on drug production and sales at a summit in November. The group's first meeting was held in Beijing last month.