Juniper_VPNFW-> unset ike gateway BRANCH2-VPN
The IKE Gateway BRANCH2-VPN is used. UNSET command abort!
Failed command – unset ike gateway BRANCH2-VPN
If this is your problem while deleting the VPN gateway in Juniper Firewall through CLI, then you need to first delete all the policies corresponding to this BRANCH2-VPN VPN. So navigate to Policy > Policies section in GUI and delete the respective policies. Now you can delete VPN IKE Gateway either through CLI using unset command or through GUI.