Nutloose, the term 'nuclear proliferation' since about the 1960's has referred to the spread of nuclear weapons to more nations having them. Your attempt at a semantic game fails.
The Non Proliferation Treaty was explicitly drawn up to prevent that spread ... with less than desired results. A variety of related arms control measures -- SALT, START, SALT II, etc ... -- have all tried to address nuclear stockpiles and in some cases, reductions of same. (with mixed success).
If Mr Trump want to increase the number of warheads, I am not sure why. If what he wants is to improve/update/upgrade the warheads currently in inventory, that makes sense. They have a shelf life.