The United States announced sanctions Tuesday on a China-based network for producing and distributing chemicals used to make drugs including those fueling a deadly national fentanyl crisis.

The US has announced sanctions on 25 China-based firms and individuals allegedly involved in the production of chemicals used to make fentanyl. Fentanyl, a potent opioid used as a painkiller or sedative, plays a major role in the ongoing US drug crisis.

The charges were the second major set of indictments the Biden administration has unsealed since June accusing Chinese companies of supplying Mexican cartels.

The United States on Tuesday announced actions against Chinese companies and people as President Joe Biden's administration targets trafficking of the deadly drug fentanyl, unsealing indictments and imposing sanctions on dozens of targets.