230
US to build new nuclear gravity bomb
(www.defensenews.com)
This is a most excellent place for technology news and articles.
China has absolutely zero interest in negotiating arms treaties, they aren't quite in a full arms race with the US. The way arms limitations treaties work is if there is a rival state that will always match or exceed your armament, then you actually have an incentive to stop. If you don't have such a rival then you can always ensure that you are on the top and ignore any treaties.
Not disagreeing with you.
China did sign the Nuclear Nonproliferation Treaty (NPT) committing to nuclear nonproliferation and disarmament.
But they're just saying they are not expanding, just modernizing!
https://www.nti.org/analysis/articles/china-nuclear-disarmament/
They are however expected to expand by about double.