Not yet.
Their leaders are still influenced by campaign contributions from those who profit from this industry; misinformation and propaganda about the usefulness, safety, and cost of nuclear weapons; fear that giving up their nuclear weapons will make them more vulnerable. Nuclear-armed countries may join the Treaty as long as they agree to a legally-binding and time-bound plan to eliminate their arsenal. Countries that host other countries nuclear weapons can also join the Treaty if they agree to stop hosting other countries nuclear weapons by a specific deadline.
Nuclear-armed countries are also exerting tremendous pressure on their allies not to sign the Treaty. Other countries which have not yet signed include the members of NATO, plus South Korea, Australia, and Japan (the only country to have been A-bombed).
BUT…
many, many countries have enormous citizen support for the total abolition of nuclear weapons, and they will eventually sign on when CITIZEN PRESSURE (that’s YOU!) is strong enough.