Having a working nuclear weapon is not the same thing as having a viable vehicle to deliver the nuclear weapon somewhere useful, unless we're talking like, suitcase nukes or whatever. It's hard for me to estimate what the timeline would be to retrofit their existing ballistic missile platform to be suitable, but it's not a super easy task - timeline in peace times would be years, most likely. War likely accelerates it... unless the key people you need for the program, the supplies, testing resources, etc., are victims of the war.
'Working nuclear weapons' is a really broad scale so it's tough to extrapolate without knowing if it means "they can send a person with a low yield weapon somewhere and blow it up vs. "they can launch a high yield weapon on a ballistic missile anywhere within 2000km"
