How to "unjoin" a device, or delete network session key?

Does Chirpstack provide a mechanism to unjoin a device, or to reset a device state within Chirpstack to before it joined? For example, I want to delete the current network session key for a particular device so that Network Server ignores confirmed uplinks until device performs a join request again.

Rather than deleting and re-registering the device and its network and application keys, it would be easier operationally to simply delete the network session key if that functionality is available to us. Or some other action that would be equivalent to “un-joining”.

Yes, this is possible, but currently through the API only.

is it also possible to just delete the Nwk_key from the Postgres table “device_keys” on the application server side?