I figure they’ve been “one or two weeks away” for at least a decade now.
Producing the fissile material is not the problem. It is overcoming “the klystron problem”. A low grade klystron will work, but it takes a LOT more fissile material and means the bomb must be a LOT larger and heavier.
A klystron is the “heart” of a weapon, and the more accurately it can detonate the explosive that blast the fissile material together, the larger the yield of the blast.
This matters because the bomb must be moved to its target, and very few missiles, for example, can carry 5 tons of payload (10,000 lbs).
And then there is the Overkill problem. Most people misunderstand Overkill. It is best described as the nuclear missile weapon failure rate. The US has one of the best Overkill in the world, estimating about 40-50% of our launches detonate on their target. Nobody else comes close.
Is there a minimal size for a nuke? Could Iran create 5lbs payloads?