pairing operation with new iphone stalled. Cannot turn iwatch off or reset. Pairing "clock display" stuckk

Try force restarting or erasing the watch

Force Restart

Put the watch on its charger puck, press and hold both the side button and Digital Crown for at least 10 seconds, then release both buttons when you see the Apple logo.

or erase like this

1. Put your watch on its charger and keep it there until you complete these steps.
2. Press and hold the side button until you see the power button in the upper-right corner of the display.
3. Press and hold the Digital Crown until you see Erase all content and settings.
4. Tap Reset, then tap Reset again to confirm.
5. Wait for the process to finish, then set up your Apple Watch again. When asked, restore from a backup.
6. 
   

Erasing all content and settings erases all media, data, and settings from your Apple Watch, but it does not remove Activation Lock if it has one.

You're welcome, good luck.