The time is running out for the Americans, these "no you first" conditions are in vain. Later on this month a good portion of the IAEA inspections will be cut. In my opinion once that is done Iran must go all out and give the Americans 2-4 weeks to completely remove all the sanctions or the following will happen:
1) Iran will completely leave the JCPOA and kick out all inspectors (i.e spies)
2) Declare it has left the NPT - leaving the NPT does not happen straight away, you need to give them few months notice.
3) It should also make it clear that its nuclear program will change in its posture i.e increase enrichment to beyond 20% and start working on developing new enrichment facilities deep underground with the aim of reaching the 1000,000 SWU target.
4) Start making more hints of Iran potentially going nuclear, like we recently saw from the the intelligence minister.
If these threats are made, then you will see how quickly these Americans will run back to the deal. The more these Americans drag their feet, the less appetite Iran will have for the JCPOA because as time goes by, Iran is adapting more and more to these sanctions. The Americans do not seem to realise they are the ones that is running out of time here.