NOT an advanced missile. Just a unusual use for an IRBM. Maybe with some intermediate correction or terminal homing. We could do that with a Minuteman or Poseidon, no problem. We just don’t have any plans for nuclear fleet busting weapons.
The question is “How would we respond?” Like “Nuke our fleet and 3 Gorges dam is GONE, sucker and then we start working over the rest of your country until heads of the upper levels of the Chinese Communist Party are delivered to us in bins.”
Why are you assuming these missles are armed with nukes?