Bloomberg reports on the matter
The report says that China is conducting a review of its rare earth policy and looking into possibly banning the export of rare earth technology to countries or companies it deems as a threat to state security, citing a person familiar with the matter.
Adding that officials view the technology needed to refine and purify the raw materials are a more powerful weapon in protecting state interests than the actual minerals itself.
In that lieu, the source said that China has no plans to restrict shipments of rare earths to the US but it is keeping such an option in its back pocket should a trade war break out again between the two countries.
However, China is said to be considering a ban on rare earth minerals as part of its sanctions on some individual companies such as Lockheed Martin, which was involved in the arms sale to Taiwan, according to the source.
I reckon this looks to be more of a warning shot by China. They're not going to risk closing off the export of rare earth minerals in general but the bolded remarks show what their intentions really are when it comes to this issue.
