Yes. China, Russia, Iran.
ChiComs sponsored Iranian nuke with their gifts of centrifuges and ring magnets.
Definitely allies of convenience. China doesn't like Muslims, as evidenced by its treatment of the Uyghers. And I think it would wet itself with delight if it could stand aside while the Europe/USA block and Russia had a serious atomic fight, leaving resource rich, population poor Siberia open to reconquest, and removing all serious rivalries to its hegemony.